


Teacher's Pet

by Freshtale_trash



Category: Undertale (Video Game)
Genre: ...probably, BDSM, Collars, Don't say I didn't warn you, Dream is hiding something, Ecto-Genitalia (Undertale), Ectobiology, Fluff and Smut, Full Consent, Gay, KILLER IS ALMOST 18, Killer is a kinky boy, Kinky, Leashes, Lots of Secrets, M/M, Master/Pet, NIGHTMARE AND MUFFET WERE NOT MARRIED, Nerd and Jock au, Nightmare is bi, Nightmare is too, Porn With Plot, Secret Relationship, Secrets, Slow To Update, Some angst, THIS HAS SEX SCENES, Teacher-Student Relationship, Teacher/Student, This is a lot of Tags, Underage Sex, skeledick, skeletons can fuck- deal with it
Language: English
Status: In-Progress
Published: 2018-03-28
Updated: 2018-08-23
Packaged: 2019-04-14 03:36:44
Rating: Mature
Warnings: Underage
Chapters: 24
Words: 23,724
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14127234
Author URL: https://archiveofourown.org/users/Freshtale_trash/pseuds/Freshtale_trash
Summary: Killer is your average high school nerd. He's always early, gets straight A's, and is known to be a goody-two-shoes by all the jocks of the school. But what happens when he looses that good-guy streak?Nightmare is an everyday high school History teacher. He's much younger than most other teachers there but is highly respected among them. Even though he can have a short temper at times, he is said to be one of the most liked staff members of the whole school. So why has his twin brother started to notice him acting different lately?When these two start a secret together, their lives become one big roller coaster. What will happen when rumor spreads? They can't keep things hidden forever, can they?





	1. Pop Quiz

**Author's Note:**

> I will warn you in these notes if the chapter you are about to read contains smut/sex

Killer smiled widely as he skipped through the school hallway. He carried a few books in his arms since they wouldn't all fit in his backpack. The bell wasn't going to ring for a few minutes yet, but Killer always like to be early for this class. It was last period; History. He wasn't actually the biggest fan of History itself, but fell in love with this class... Well, the teacher of this class.

Killer knew it wasn't right but couldn't help constantly daydreaming of his history teacher, Mr.Nightmare. He waved at Nightmare as he entered the classroom. Nightmare smiled and waved back happily. 

Nightmare always had a certain fondness for Killer. He was a straight-A student and always early with everything. Although he'd never admit it to anyone, Nightmare actually found Killer quite cute... Maybe too much so.

Killer sat down at his desk, which also happens to be the closest desk to Nightmare's. He set his books down and his backpack next to him. Nightmare had looked back down at the papers on his desk, still sorting through some things from the last class. Killer smiled as he watched the older male, starting to mindlessly doodle little hearts around Nightmare's name in his personal notebook. He often doodled and sketched drawings of his teacher whenever he got the chance but kept it all in his private notebook so nobody knew. 

Other students started to file in and a couple of them gave Killer dirty looks; the jocks. Undyne was one of the biggest bullies of the school. She'd pick on anyone she got the chance to and, of course, Killer got stuck sitting next to her in this class of all things. Undyne carelessly tossed her backpack down as she sat. Her gaze shifted to Killer's notebook and she leaned over to try to read what it said. Killer immediately hid the page against his chest so she couldn't see it, a faint blush dusting his cheeks.

Undyne chuckled darkly as she teased him "what's wrong? Is that your diary?" Killer just stayed silent and closed the notebook completely. He set it back down on his desk and looked forward at Nightmare again. Undyne rolled her eyes, scoffing "whatever." 

The bell overhead rang and all of the students quickly shut up as Nightmare stood. He gazed over the classroom and silently took attendance on the clipboard he was holding. Only a few kids were missing but most of them were jocks. 

Jocks were often known to skip classes and slack off a lot more than nerds. The whole school has been segregated like this since as far back as anyone can remember. If you ever became a student here, you were automatically titled a nerd or a jock. 

Nerds were always the ones to be targeted by bullies and bullies were always titled to be jocks. It's practically tradition at this point. Killer, himself, was considered a nerd since the first day of his freshman year. He's a senior by now but the school year had only just started a couple weeks ago.

Killer was snapped out of his thoughts when he heard the clipboard hit Nightmare's desk as he set it down. A piece of chalk was dragged across the board up front, making a slightly irritating noise as it left a trail of white to spell out "pop quiz".  
A sea of groans was heard among the students when they read what Nightmare had written. But, unlike everyone else, Killer smiled at that. He actually quite enjoyed tests for this class. Tests meant that he could impress Nightmare if he did well. And if he did impress him, then he would get praised for his work.

Nightmare started to hand out the tests "as soon as you get your test, you may start." He smiled when he handed Killer's to him. 

Killer immediately wrote his name and started to answer. But, the second he read over the first question, he realized he didn't actually know what to do. His eyes quickly scanned over the entire test without knowing a single answer. 

Killer started to panic that he'd do awful. He attempted to remember anything from the past few lessons but all that came to his head was Nightmare's voice and not the actual words he had said. His memory came back and he mentally yelled at himself from the realization; he'd been daydreaming through practically everything lately. 

The clock suddenly sounded louder with every tick as Killer got stressed, terrified that he'd loose Nightmare's respect if he failed. He strained to understand any of the questions with no luck. His vision started to blur with tears and he felt his breathing get faster, hyperventilating slightly. Killer went into a state of panic and quickly put his head in his hands to hide his tears. 

Nightmare glanced up calmly but immediately perked up when he noticed Killer's distress. He stood and walked over, crouching next to Killer's desk and trying to look him in the eyes. He lowered his voice so the other students wouldn't look over "are you ok, Killer?"

Killer flinched at Nightmare's voice and slowly looked over at him. Nightmare gave a reassuring smile, only making Killer cry harder. The bell still wouldn't ring for a long time which just made the clock sound even louder at knowing that. Time went agonizingly slow to Killer since he just wanted out of this whole situation. 

Nightmare gently frowned as he glanced around them "here... let's go in the hallway so other students won't stare..." Killer faintly nodded, even though being alone with Nightmare seemed to be the absolute worst thing to do right now.  
Nightmare stood again and offered a hand. Killer glanced at Nightmare's hand but didn't take it, standing on his own and shoving his hands in his pockets, looking down.

Nightmare felt bad but led the way out of the classroom. A few students started to watch them and Nightmare glared in their direction. The kids just looked back down at their papers again, intimidated by the older male. 

Killer tried not to take notice of the other students gazes on him as he trailed behind Nightmare. Nightmare gave one last glare at the kids, making sure they'd keep working when he left, before closing the door so it was just him and Killer alone in the hallway.


	2. I Could Never Hate You

Killer leaned his back against a locker and slid down it until he was sitting on the floor. Nightmare sighed silently as he crouched down in front of Killer. Killer cried harder, making him choke on his words "I-I'm s-orry Mr.N-Nightmare..."

Nightmare gave Killer a sympathetic look "why are you sorry?"

"I-I-I d-didn't pay attention... I was going t-to fail the quiz, a-and then you'd h-hate me and never w-ant to talk to me a-again..." Killer refused to look up from the ground, not wanting to see the disappointment in Nightmare's eyes. He spoke quickly, nervous as to what Nightmare might think. "I-I couldn't pay at-tention. My mind... I can't help but daydream e-every time you speak, and my soul goes crazy whenever you say my name! I just want to be by you all the time and have you call me yours! You make me melt everyday and I can't help it; I love you, Mr.Nightmare!..." 

Nightmare was speechless. He stared slightly as his mind tried to process everything Killer had just admitted. "Killer, I..." Nightmare's eye lights darted back and forth in thought, his gaze at the ground. He'd never even thought this a possibility until now. His mind went back to how many times he'd noticed Killer daydreaming during class, finally able to link it to himself as the cause. He slowly looked over at Killer again and glanced at his teeth when a thought crossed his mind. 

Killer hesitantly looked back up to meet Nightmare's gaze but didn't notice his glance. Fear of rejection stung in his brain, yet it's what he expected to happen. After all, Nightmare was with Muffet, wasn't he?

Nightmare paused before very gently caressing Killer's cheek. He looked him deep in the eyes, talking again in a gentle, caring tone "Killer... I didn't know you felt this way... I... like you too..."  
Killer's eye lights showed dimly with hope as he gazed into Nightmare's "r-really?..." 

"Yeah..." Nightmare smiled and gently rubbed Killer's cheek with his thumb, wiping away tears. "You're the sweetest person I've ever met and I could never hate you." 

Killer faintly smiled and leaned into Nightmare's touch "thank you..." 

"Never think that I will hate you in any way, because I won't. You're my favorite student and my favorite person... I promise."

Killer blushed and sighed silently in relief. It felt good to finally just say all of that. He gently smiled at Nightmare's caring nature. It was something that Killer definitely loved the most about him; though he could be very tough and cold, he was still really caring when it came down to it.

Nightmare smiled sincerely and gently hugged Killer "don't worry about that silly little quiz. I would never think any less of you just because of one bad grade." He closed his eyes in content, happy that Killer had told him what was going on so he could comfort him.

Killer faintly smiled and hugged back. His soul fluttered like a love-sick puppy, feeling safe and protected in Nightmare's arms. They stayed like that for a while before Killer slowly pulled back from the hug. He sniffled and smiled sincerely at Nightmare. "Thank you, Mr.Nightmare..." He repeated with a soft and sweet tone to his voice. 

"Of course, Killer. I will always be here when you need me. Don't be scared to talk to me about anything, I'm here for you no matter what" Nightmare gave a reassuring smile. 

Killer's smile faltered slightly "you... don't hate me for all of that?... I... what I said... I-I-" 

Nightmare cut Killer off, pecking a very gentle kiss on his forehead "I just told you that I could never hate you, didn't I? Killer, I don't hate that you love me. In fact, it makes me happy to know that you feel that way. I hadn't realized any of this before and I'm glad you opened my eyes to it. You really are special to me, ok?..."

"But..." Killer frowned and looked away. "Wh-what about Muffet?..."

"I'll figure it all out, Killer, please don't worry about that. That is my responsibility to work out, not yours to stress about, alright?" Nightmare smiled softly and had Killer look him in the eyes again. He continued after a moment of silence between the two "do you think you can go back into class now?"

Killer faintly smiled and nodded "I think so..."

"Alright... I'll tell you what, you don't have to take the quiz right now. You can take it later and, if you want, I could help you learn it all personally... Like a tutor" Nightmare smiled sweetly. 

Killer faintly blushed at that idea 'a study date...'


	3. You Might Want This

The bell rang overhead, students immediately rushing to leave. Killer took his time to pack up his things since he didn't want to get trapped in the swarm of people trying to get out of here. He smiled softly to himself as he slung his backpack over his shoulder and grabbed his extra books.

Nightmare stopped Killer on his way out "Killer. Here, I just realized that you might want this if I'm going to be tutoring you." He handed Killer a small slip with a phone number written down on it.

Killer blushed, taking the paper "th-thank you, Mr.Nightmare..." Nightmare smiled and nodded a 'you're welcome'. Killer hurried out of the room with the number, not wanting to embarrass himself in front of Nightmare. He made a beeline towards the bus since he didn't have to stop at his locker. His hardly visible eye lights stared straight, yet he could still feel other students looking at him from how flustered he was. 

Nightmare smiled and chuckled silently to himself 'cute...' He sighed happily and went to shove his stuff in his bag so he could leave. He picked up his bag and turned back towards the door, jumping and almost yelling in surprise at Dream standing directly in front of him. "What the hell?! Don't you make any noise when you walk?!"

Dream shrugged "I guess not. Anyways, we should probably hurry out. I've got a lot of grading to do tonight and then I have to head out to meet up with someone later. Oh yeah, you're gonna be home alone tonight without the car, by the way." Dream rambled on "good luck finding something to do. Though, you might have stuff to grade too and I'm just assuming you don't. Then again-"

"Yes, I get it, Dream. I'll be stuck at home alone. You don't have to explain" Nightmare rolled his eyes. "Though I'm still pissed that we only have one car between the two of us."

"Not my fault you like to waste your money" Dream stated simply. "Besides, I paid for the majority of this car, so I am the designated driver."

"Ok, first off, I'm not 'wasting my money'. I'm using it on useful things that I need." Nightmare huffed softly.

Dream raised a nonexistent brow, "you 'need' horror movies and useless maps of places you've never even been to?"

"They aren't useless!" Nightmare went to explain how they weren't useless but ended up saying nothing about it. "... And yes, I do need them."  
"More than you need a car?" 

"Just shut up and let's go!" Nightmare pushed past Dream, making Dream laugh softly. Nightmare attempted to ignore him as he got into the passenger seat of the car. He put his bag at his feet as he shut the door and took out his cellphone.

Dream set his bag in the back before getting in the driver seat. He glanced over at Nightmare and put the key in the ignition, saying nothing since Nightmare was very obviously avoiding conversation.

Nightmare stared at his phone's home screen as if he was waiting for something to happen. To be honest, he was really hoping that Killer would have texted him already, but he didn't. Nightmare softly sighed and opened up a social media site. He mindlessly scrolled through controversial topics and pictures of people's dogs. His mind wandered, not even paying attention to his phone as he kept scrolling.

"So..." Dream attempted to break the silence between them. He glanced at Nightmare but quickly looked back to the road. "How was your day?" 

Nightmare shrugged and made an 'I don't know' sound, not bothering with a real response. Dream just silently sighed, shutting up again. They sat in a somewhat uncomfortable silence the rest of the drive home.

~

Killer's hand shook slightly as he held the small slip of paper Nightmare had gave him. He read it over again and again, feeling as though this must be a dream. 

The bus stopped for the third time since they had left the school grounds: Killer's stop. He stood and carefully put the paper back into his sweatshirt pocket before starting towards the front of the bus. He'd been sitting in the back to avoid attention, yet that also meant that everyone would stare at him as he walked past them to get off of the bus. 

His eyes widened slightly when he felt his foot catch on something, loosing his balance. He fumbled to catch himself with his arms as he fell forward. A thud and then laughter could be heard throughout the bus. 'They did that on purpose!' Killer growled under his breath but took a breath to keep his cool. 

He slowly stood again, seeing the bus driver look back at him with a genuinely concerned look "you okay, kid?" Killer lightly nodded but said nothing, collecting his stuff up again and getting off the bus much quicker. This wasn't the first time someone had tripped him and he knew damn well that it wouldn't be the last either. 

Killer looked over his arms a bit as he made his way up the few stairs that led to an apartment building's main door. No scrapes or bruises were visible and the fall didn't actually hurt all that much, it was just humiliating. 

He walked through the door and headed up the long, winding stairs to the fifth floor. Although he wasn't technically eighteen yet, people believed him when he said he was. Plus, having a 'friend' to pull some strings helped so Killer could get an apartment for himself. It wasn't much but honestly Killer didn't need much. He didn't mind having a smaller place since it was just him anyways. Besides, he enjoyed living alone. Unlike most people his age, he liked cooking and organizing and doing all of the various chores around the house.

Killer set his backpack next to one of two seats at the table near the middle of what he considered the living room, kitchen, and dining room. He locked the door before taking out a few binders and starting on his homework with a soft smile, figuring he'd contact Nightmare later when he gained the courage to do so.


	4. Home Alone

**Notes for the Chapter:**

> This has solo smut (aka Nightmare is masturbating)

Seven at night: Nightmare sighed. Dream was still out and Killer had yet to text him. He layed on the couch, staring at his phone. A groan left his mouth as he began to think out loud. "Ugh! I'm so bored! Why hasn't Killer messaged me yet?... Maybe... He forgot? No, he wouldn't forget... He could've gotten busy. Yeah, he's just busy, that's it... Oh who am I kidding? He doesn't want to be tutored by me, let alone get personal with me..."

Nightmare shifted and sat up, shoving his phone into his pants pocket. He put his head in his hands. "Why?... Why him?... He's my student... He's 17! I'm in my twenties! God damn it... Is this really what I've become?... Some creep who actually expects him to like me back?... Ha..." 

Nightmare felt tears sting behind his eyes but he fought them off. "No... It's so wrong, but... It just feels right..." He stood and went towards his bedroom. He shut the door and sat on the edge of his bed. The feeling of tears diminished as he thought to himself, "if I don't bother him with it... Ugh, no... I'm so disgusting..."

Nightmare shifted, feeling opposing thoughts clutter his mind. He groaned and looked down at himself. A different thought hit him and he bit his bottom lip. 'No..'

He imagined Killer being there... Below him, down on his knees in worship and obedience. His eyes squeezed closed tightly and he shook his head in an attempt to get rid of the thought. The fantasy wouldn't leave him alone; a shimmering collar around Killer's neck with a leash attached to it, gripped firmly in Nightmare's hand. Killer stared up at Nightmare with a purely submissive look, waiting for a command. 

Nightmare felt his pants tighten and mentally cursed at himself. He gave up fighting it. 'Nobody needs to know my thoughts or what I do alone... This will be fine...'

He went over to his closet and moved things off a top shelf, grabbing a relatively small box from under an old shirt that doesn't fit him anymore. His hands lightly held the box as if it had something priceless inside of it. He went back over to his bed before setting the box down and opening it. 

A light gray collar sat delicately inside of it. It was simple with a soft fur inner-lining. There was a small leather patch sewn on the inside, perfectly rectangular, with a vibrant red that stuck out, which spelt out "Master: Nightmare". 

He blushed just at the sight of it, having made it in the delusion that he could give it to somebody special in the future.

A simpler black leash lay folded underneath it in the box, Nightmare took that out as well before setting the box aside carefully. He attached the leash to the collar and gently placed the collar around one of the four posts of his bed. His hand fidgeted with the leash for a second before he layed down on the bed.

He bit his bottom lip and gripped the leash firmly with his right hand as his left trailed slowly down his chest. His left hand unbuttoned his top in a sensual way, but didn't take it off once it was fully unbuttoned. He closed his eyes as he undid his pants and slid them off, kicking them onto the floor. His breath hitched at the cold air hitting his member, letting his fantasies run wild while he lightly grasped his hard-on and started to pump himself. 

Killer's back arched as he bounced, riding Nightmare. The collar showed boldly around his neck and he moaned out 'master!~'

Nightmare tugged harshly at the leash, moving his hand faster. Soft pants and moans left his mouth as he started to thrust up into his hand. 

Killer moaned louder, his tongue lolling out of his mouth in pleasure as Nightmare thrusted up against his bounces and yanked on his collar. His moans of ecstasy filled the room 'master!~ You're so big!~ You're going to make me c-ah-um!~' 

Nightmare smirked as he felt a coiling start in his stomach. "Not until I do, pet~" He squeezed slightly as he roughly pumped himself. "Mmm~ Fuck~ You're so fucking tight for me~" 

Killer cried out in pleasure when Nightmare hit his sweet spot, unable to hold it, cumming hard onto his chest.

Nightmare's smirk grew as he moaned and thrusted up hard into his hand, releasing onto himself. He panted softly while coming down from his high. 

Killer heavily panted and leaned onto Nightmare's chest 'I'm sorry master~ hah~ I-I couldn't hold it~'

"It's alright kitten~ I love you~" Nightmare smiled softly, letting go of the leash.

Killer smiled back and nuzzled him 'I love you too, Mr.Nightmare.'

Nightmare slowly let his eyes flutter open to reality again. His smile faltered at remembering that it wasn't real but he still sighed happily. He took a second to catch his breath before sitting up and shakily standing. He quickly caught his balance and took the collar off of his bed, unattaching the leash. They were placed back into the box with care and set back into the closet before Nightmare grabbed clean pajamas. He peeked outside just in case Dream had come home, seeing the hall empty and hearing nothing besides himself and the soft hum of the air conditioning. He exhaled a sigh of relief while leaving to the bathroom for a nice warm shower.


	5. Mr.Nightmare Will Be So Disappointed In Me

-over the past night-

Killer yawned and set his pencil down as he finished his homework. He smiled softly and glanced at his phone, which he'd set down on the table earlier. A silent sigh left his mouth as he thought it over a bit.

He picked up his phone and decided to text Nightmare, having calmed down a bit and worked up the courage. His hand reached into his sweatshirt pocket and felt around a bit. His eyes go wide, feeling nothing. He quickly checks the other pocket, then his pants pockets: no luck. Killer began frantically searching his backpack, the floor, table, and seat in case he had dropped it inside. 

Sudden realization hit him. 'I must have dropped it when I tripped on the bus! Mr.Nightmare will be so disappointed in me!' Killer whined silently and held himself. Tears threatened to form but he tried to stop them, knowing he was getting too emotional about this. 

He looked over at his phone again and picked it up, attempting to remember the number without the paper. He tried a few things but nothing seemed right. 

Killer frowned and set his phone back on the table before heading to his room. He took off his sweatshirt and crawled into bed, not bothering to get changed. The blanket was pulled over him as he curled up and closed his eyes in hopes that he could just fall asleep and forget about it. 

-the next day-

Killer kept his head down as he walked into history class. He hugged his books close to his chest, assuming that Nightmare would be very mad at him for not texting. His grip tightened on his things when he heard Nightmare's voice.

"Hello Killer" Nightmare smiled softly. He seemed in a good mood as always, having tried to brush off everything that had happened last night. His smile faltered in noticing how sad and scared Killer was acting. 

Killer sat down at his desk without saying anything at all. His gaze stayed down at his books in order to avoid eye contact. 

Nightmare sighed softly and went over to Killer, crouching down "Killer?... Are you alright?..." He kind of wanted to apologize since he felt like it was his fault, but tried to not mention yesterday. 

"I..." Killer shuddered slightly. "I-I'm sorry Mr.Nightmare..." 

Nightmare sighed "why are you apologizing again?..."

"Because I promised you that I'd text... and I didn't..." Killer closed his eyes tightly so he wouldn't see any disappointment on Nightmare's face. 

"Killer, I'm not mad at you. I will admit that I was a bit confused last night since you didn't contact me, but I'm not mad or disappointed. Remember what I told you yesterday? It still stands." His thoughts continued talking when his mouth stopped. 'I just hope that you think the same...' 

Killer slowly looked up from his desk, his eye lights meeting Nightmare's caring gaze "I... I lost it..."

"Hm?" Nightmare couldn't quite understand, especially since Killer was somewhat mumbling. 

"I lost the paper you gave me..." Killer stopped himself from explaining everything exactly how it happened, simply acting like it was completely his fault. "I accidentally tripped on the way home and must have dropped it on the ground... I'm sorry I wasn't more careful..."

Nightmare suddenly felt stupid for thinking that Killer hated him. He silently chuckled at his own previous thoughts 'of course! He dropped it! I can't believe I didn't even think of that!' Killer looked slightly hurt, thinking that Nightmare was laughing at him. Nightmare noticed and quickly explained his chuckling "sorry Killer. I'm just glad that's all that happened. Here, I can actually just put the number in your phone for you. That way you can't lose it." 

Killer lightly nodded, taking his phone from his pocket and unlocking it before handing it over to Nightmare. Nightmare gently took it. His fingers typed out the number on memory and simply named his contact 'Mr.Nightmare' since Killer always called him that. He handed the phone back as Killer smiled sheepishly at him. 

Killer softly blushed "th-thank you Mr.Nightmare..."

Nightmare nodded lightly and other kids started to file in and take their seats as well. He thought for second before standing. His voice was relatively low when he spoke to Killer "would tonight or tomorrow work?"

Killer was confused for a second but it quickly clicked in his mind "yeah... Tonight would be nice..."

Nightmare smiled again "alright. Can you contact me right after class?" Killer nodded softly, actually meaning it this time. This was his chance to be alone with Nightmare and he would not let himself screw up again. Nightmare gladly turned back and walked over to his desk again with a genuine smile. 

Killer avoided her gaze as Undyne sat down in her seat, staring at Killer to make him uncomfortable. She whispered so Nightmare wouldn't hear but Killer would "nice going crying yesterday, you wimp. That's one way to get the teacher's attention isn't it? Pffft, teacher's pet." She rolled her eyes before turning away from him.

Killer erupted in blush at being called that, crossing his arms on his desk and burying his face in them to hide his blush. Thoughts clouded his head but he attempted to quickly get rid of them right away. It was one of his biggest fantasies to have Nightmare call him pet. He mentally whined 'not at school...' His mind slowly cleared itself of the lewd thoughts. 

Killer slightly jumped when the bell sounded loudly for the beginning of class. He immediately looked up again, having gotten rid of his blush for the most part. How was he going to keep from getting lost in his fantasies when he was alone with Nightmare for tutoring?


	6. You Don't Have To Use That Title Here

Nightmare layed on his stomach, his pillow under his elbows, in a position that normally teenage girls would be caught doing. He stared at the time on his phone as he watched it change: four-thirty-eight, four-thirty-nine... His smile was wide while he texted Killer, who was agreed upon to come over at four-forty-five. He'd given Killer a contact now, it just being his normal name since Nightmare couldn't think of an appropriate nickname for him. 

A knock sounded through the house at exactly four-forty-three. Nightmare bolted up and quickly went to answer the door. Dream was out of the house again since he said he had an important meeting with Ink and Blueberry. Nightmare didn't question it since those three have been good friends for a while. 

The door opened to see Killer standing there. Killer smiled widely up at Nightmare and a faint blush dusted his cheekbones. "Hi Mr.Nightmare" he waved and rocked on his heels cutely. 

Nightmare barely managed to keep himself from blushing at Killer's adorable stature. "Hello Killer" he smiled back and stepped aside so Killer could come in. Killer gladly went inside but stayed just inside the door, gazing around the front room. Nightmare closed the door behind them and walked out into the room more "you can leave your shoes at the door."

Killer kicked his shoes off and lined them up against the wall before stepping onto the shaggy carpet. "Thank you for inviting me over, Mr.Nightmare."

"Of course. And you don't have to use that title here; just call me Nightmare" he smiled brightly as Killer slightly adjusted his backpack on his back. 

Killer gazed at Nightmare in sort of shock and shook his head "n-no. I call you Mr.Nightmare as a sign of respect, not because you're my teacher." 

Nightmare was a bit surprised but smiled "alright... Where do you want to go to start? We can go to my room or the kitchen if you'd like, or we can stay here." 

Killer softly blushed when Nightmare gave his room as am option. 'He trusts me enough to let me in his room?...' "Um... C-can we go to your room?... I-I just feel more comfortable studying in a bedroom..." He lied. This was simply his best excuse to see Nightmare's room.

"Sure" Nightmare didn't seem fazed since he was the one to give it as an option in the first place. He smiled and signaled for Killer to follow, heading to his room, which was the closest door to the end of the hallway. Killer sort of fidgeted with his backpack strap as he followed shyly. They passed Dreams door and the bathroom, Dream's door being closed. "Here" Nightmare smiled and opened the door to let Killer in first.

Killer nodded a 'thank you' as he walked in. He gazed around the sort of dark room. The walls were a dark gray and the floor was a darker type of wood. Nightmare had a queen sized bed near the corner and a dresser with various other items on it. Thankfully, he kept his room pretty clean, especially once he knew Killer was coming over. Nightmare closed the door behind them as habit without thinking much of it. 

"This is it. It's not much but I like it that way" Nightmare smiled softly and walked over to his bed, sitting down. Killer smiled brightly while still gently blushing. He went over and put his backpack down as he sat next to the older male. 

Killer gazed up at Nightmare in amazement. His eye lights showed faintly and his blush deepened, extremely happy to be in his crush's room with him. "Mr.Nightmare..."

Nightmare looked down at Killer and blushed a tiny bit at seeing his beautiful eyes "yes Killer?"

"Thank you... For letting me come over..." Killer gave an adorably gentle smile.

Nightmare's blush spread greatly and he stuttered a bit at Killer's expression "oh... O-of course-"

"I love you..." Killer mumbled, sort of interrupting him.

Nightmare erupted in blush and looked away slightly, flustered. Killer seemed to have a new found confidence as Nightmare slowly looked back at Killer and went to say something. Killer suddenly grasped Nightmare's shirt and tugged him closer, clinking their teeth together in a gentle kiss. Nightmare's eyes widened but quickly closed as he went to kiss back. 

Killer pulled back, leaving the kiss at a little peck. He blushed immensely and quickly looked away. "I'm sorry Mr.Nightmare! I don't know why I did that..."

"No, i-it's ok" Nightmare chuckled a bit nervously. He lowered has voice to a sort of mumbling tone "I... Kinda liked it..."

Killer flustered even more, hearing Nightmare say that. He slowly looked back at him. Their eye lights met and Nightmare lightly glanced at Killer's teeth and then his eyes again. Killer immediately caught on and did the same action. Nightmare gently smiled and hesitantly caressed Killer's cheek, them both blushing like crazy. He slowly fluttered his eyes closed while inching closer until their teeth met again. 

Killer smiled into the kiss and wrapped his arms around Nightmare's neck as he kissed back. They held it like that for a bit before Nightmare slowly pulled back, their teeth parting from each others once more. Killer kept his arms there but Nightmare lightly moved his hand off of Killer's cheek. Their eyes opened after a moment and their blushing had died down a bit. 

Nightmare gazed into Killer's eye lights which now shone brightly in happiness. He smiled and softly pecked his teeth once. "I love you, Killer..." His voice was a gentle whisper when he spoke. 

Killer's blush showed a bit more again and he smiled uncontrollably "I love you too, Mr.Nightmare..." Nightmare pressed their foreheads together lovingly and silently sighed in content. They stayed like that for a little until Killer let his arms drop back to his sides and pulled away slightly. He sweetly giggled and turned away, leaning down and unzipping his backpack "so... The middle-east, huh?"

Nightmare blushed and chuckled while relaxing against the soft mattress a bit more "heh, right."


	7. You Think I'm Lying To You?

Killer glanced at the time on his phone after a while of studying "oh, it's getting kind of late. I should probably head home for dinner. Thank you for having me over though, Mr.Nightmare." He smiled brightly and started to pack up his things.

Nightmare smiled back happily "of course. We didn't get through everything, so you can come back another day if you'd like."

Killer slung his backpack over his shoulder again before turning back towards Nightmare "yeah... I'd like that." He opened the door and waved softly, heading outside.

"Hey Killer..." Nightmare called after him a bit.

Killer turned around to look at him again "yes, Mr.Nightmare?"

"Are you walking?..."

"Oh, uh, yeah... I like walking. Besides, it's not that far" He smiled, not really wanting to tell Nightmare about his living situation yet.

"Alright..." Nightmare was hesitant but knew he couldn't really do anything about it anyways, since Dream took the car again. He lightly smiled "I'll see you tomorrow at school though."

"Yeah" Killer smiled back brightly and very faintly blushed. He turned away from the house and started his pretty long walk home. He knew his way back from walking there earlier that afternoon but it was darker out now and he was taking his time, unlike the walk there in the first place.

Nightmare waved softly and sighed in content. Just a few minutes after Killer left, Dream pulled into the driveway. The cars headlights turned off as Dream got out and shut the door. He turned towards Nightmare and gave a confused look, having not seen Killer leave "what are you doing outside?"

"Just... Looking at the clouds..." Nightmare shrugged and headed back inside again. Dream didn't believe his brother but followed him anyways. He shut and locked the front door before taking his shoes off and setting them aside. 

Nightmare noticed Dream's skeptical look at him and simply pat the shorter's head. He went towards the kitchen without another word, looking through the fridge for anything easy to make. Dream pouted at the pat. He didn't like being treated as though he was a child. He was technically born a little bit before Nightmare, but he was treated like he was younger because of his attitude and height. 

"Don't treat me like a kid, Nightmare" Dream huffed as he grabbed a cup from the cupboard and filled it with water, sitting down to drink it. He sighed and took off the jacket he was wearing. The jacket got carelessly tossed onto the counter, making some money and chapstick slide out of the pocket.

Nightmare chuckled softly and shut the fridge since he didn't really see any thing he wanted "then don't act like one." He went over and picked up the money that Dream had in his jacket. "A twenty and a five? Why were you just carrying this with you?"

"Because we went out to dinner as a group as I paid for myself. That was the change" Dream stated plainly while ignoring Nightmare's earlier comment. He reached for the bills "now give it back."

Nightmare raised a brow, skeptical "exactly twenty-five dollars change?" 

"What are you implying? You think I'm lying to you?" Dream crossed his arms.

"Yes, actually" Nightmare stated simply. 

"Oh yeah? And how do you think I got the money then?" Dream sighed, rolling his eyes. 

"I think that Ink or Blue paid you for something..." Nightmare seemed to think for a second. "I also happened to notice one of my favorite movies missing... And I know that you hate them-"

"You know what? Fine! Yeah, I sold your freaking movie! Happy? Maybe if you would actually pay attention to me on our birthday than I wouldn't be taking your stuff!" Dream huffed and tried to snatch the money back from Nightmare. 

Nightmare held it above his head so Dream couldn't reach it "my movie, my money. I never gave you permission to take it, so you can't keep the money when I paid for that movie to begin with."

"Fine!" Dream just stood and stormed off to his room, slamming the door. Nightmare rolled his eyes at Dream's overexaggeration and pocketed the money. He turned to the pantry since he was still hungry anyways. His eyes scanned over everything and settled on some ramen noodles, taking them out to cook for his dinner.


	8. I Can't Believe You!

Nightmare's eyes went wide and he held his cheek in pain "ow... Ok, I deserved that..."

"I can't believe you!" Muffet shouted, knowing that people outside the teachers lounge could probably hear her. "To think I actually thought you were a loyal boyfriend!" Tears stung her eyes "if you're leaving me for some fucking slut, I swear-!"

"No" Nightmare sighed. "Muffet, look, I'm just really confused about things right now and need time to think everything over..."

"So you break up with me in the fucking teachers lounge!? I was actually going to ask if you wanted to see a movie on Friday, but i guess not! You know what? Fuck you! What if I just went and fucked Dream now, huh?! I mean, it's not like we're together anymore!" Tears traced her cheeks, making her makeup run a bit. 

Nightmare just frowned and tried his best to stay calm through Muffet's yelling. He already knew Dream and Muffet would never actually get together and Muffet was just completely talking off of anger at this point. He stayed silent but couldn't help contradicting her statements in his thoughts. 'At least it was in person and not through text... Not like I wanted to see that movie anyways... Dream is gay, he would never agree to date you...'

"I better not hear of you fucking random sluts now or you'll get more than a slap from me! Don't even bother ever talking to me again you asshole!" Muffet cried harder and practically ran out of the room, to the girls bathroom.

Nightmare sighed, actually glad to get that off of his chest, yet he still somewhat felt bad for her. He frowned and sat down on a couch. His head rested in his hands as the door creaked open. 

"Geez, are you alright?..." Dream gave a look of genuine concern. "She went off on you bad, huh?..." He walked more into the room and sat beside Nightmare, putting a hand on his shoulder.

Nightmare glanced over at Dream with a slight smile "yeah... I kinda figured she would react like that..."

"Your cheek has a mark on it..." Dream pointed out with a kind tone of voice. There was somewhat an outline of a hand from how hard Muffet slapped him. 

Nightmare shrugged it off "it's fine... I'm sorry by the way..."

"Huh?" Dream let his hand drop to his side instead of Nightmare's shoulder. "What are you sorry for?"

"Forgetting about you... On our last birthday... I just got caught up on other things, and I kinda forgot I was a twin..." He hesitantly chuckled. "I didn't mean to make it all about me..."

"Oh..." Dream softly smiled. "It's ok; really. Sorry I went off on you last night. I overreacted..." 

"It's alright..." Nightmare sighed as he slightly leaned against Dream, resting his head on his shoulder. Dream wrapped an arm around him and reassuringly rubbed his shoulder. A soft smile made it's way onto Dream's face. They sat there for a bit until the bell for everyone to come inside for the beginning of the day sounded overhead. 

Nightmare gently pulled away and stood. He looked back at Dream "is it still there?..."

Dream was confused for a second but quickly realized what Nightmare was talking about. "Your cheek is still kind of red but you can't tell what from." 

Nightmare nodded in understanding and started out of the room. He saw Muffet come out of the bathroom and their eyes met again for a second, pure hurt and anger on her face. Nightmare immediately looked away and just kept walking. His gaze slowly shifted back up to what was in front of him as he made his way to his classroom.

Killer was stood at his locker and smiled softly at Nightmare when he walked by him. He quickly noticed the red on Nightmare's cheek and his aura being sadder than usual. His smile faltered as Nightmare didn't even see him. Something was wrong...

Nightmare sat down at his desk and shuffled through a few papers. He silently sorted them into different piles for each class he taught. 

Killer peeked into Nightmare's room and gently knocked on the open door "Mr.Nightmare?..." 

Nightmare looked over and smiled "hello Killer. Did you want something?" He turned away from the papers he was sorting.

"Actually..." Killer took one step into the room but didn't go any further. "I was wondering if you're ok... You looked out of it when I saw you in the hallway... Did something happen?..."

"Oh" Nightmare looked away for a second before looking back. "I'm fine, Killer. I just got into an argument with someone." 

"Really?... Why?" Killer quickly added so he wouldn't be rude "sorry! I don't mean to intrude or anything... You don't have to tell me..."

"No, it's alright" Nightmare sighed. "I broke up with Muffet. She... Got upset and started arguing, but I'm fine." 

Killer was surprised. He didn't know if he should be happy that they broke up or feel bad for Nightmare. "Oh... I'm sorry..."

"It's really alright, Killer. I'm the one that broke up with her anyways. And to be honest... I kind of wanted to for a while now..." Nightmare shyly chuckled. "Besides... I really don't want to cheat..."

Killer faintly blushed at that, knowing that Nightmare was referring to their kiss last night. "Right..." He looked away shyly for a second but slowly looked back. Nightmare smiled softly at Killer but they both jumped at the loud bell telling students to get to their first class. "Sorry, Mr.Nightmare, but I have to get to my class... I'll talk to you after history, ok?" Killer smiled as slowly started out the door.

Nightmare nodded lightly in agreement "alright. Get off to your class then, I don't want you late because of me." He smiled and could compose his usual, happier stature after their conversation. Killer nodded as he turned around and quickly hurried off to his first class; art.


	9. What's Going On, Dream?!

**Notes for the Chapter:**

> Start of lots of angst here, be prepared.

The bell sounded for the end of the day but Killer stayed back again. He smiled brightly at Nightmare once he finally stood up with all of his stuff. The other students were practically all out the door a second after the bell rang. Killer walked up to Nightmare "are you feeling better, Mr.Nightmare?..."

Nightmare smiled sweetly and turned all of his attention to Killer "yeah, it was just the stress of the moment. I'm alright now." 

Killer shifted his books in his arms, trying to think of something to say "I... Don't want to get too off from where everyone else is in the learning... Do you think I could come over again today?... Y'know, just so I don't fall behind quickly..." Killer's blush and shy tone of voice kind of gave away that he was lying about why he wanted to go over. 

"Oh..." Nightmare smiled softly but thought for a moment. "I think Dream will be home all afternoon today... But you can still come over if you'd like." Killer smiled and nodded. "Alright... uh, Killer, don't you have to catch the bus?" 

Killer perked up and immediately started to leave "sorry Mr.Nightmare! I totally forgot! I'll text you though!" He quickly turned and ran so the bus wouldn't leave without him. 

Nightmare chuckled lightly at Killer being cute again. Dream stepped in and tossed the keys to Nightmare, him barely able to catch them even with his good reaction time. He gave Dream a confused look.

"You're driving today. I have to text someone about something important so I can't be behind the wheel when I do" Dream stated plainly. "Let's go."

"O...k...?" Nightmare grabbed his bag and followed Dream. "You seem in a hurry today... Is something going on?"

"Yeah, I'm just a bit upset" Dream sighed and gazed down at his phone as if the two had switched roles suddenly.

Nightmare was still confused but didn't ask anymore questions. He got into the drivers seat and started the car as Dream got in the passenger's, staring at his phone. 'Is this what Dream feels like everyday?...' Dream's thumbs typed away at his phone while Nightmare just tried to ignore him. 

Not even halfway through their drive home, Dream's phone rang with what Nightmare found as a really annoying ringtone. Dream groaned and answered it. Nightmare couldn't help listening in but still keeping his eyes on the road.

"Yes?... No... I already told you that I'm busy... Yes, I-... No... No... Look, I have important things to do at home and I don't have time-..." Dream's tone suddenly softened. "Wait, what?... Are you serious?... I... Fine... Ok... Yes... Yes, I get it... Bye." He hung up and sighed. His attention turned to Nightmare and spoke more clearly so he knew he was talking to him "apparently I have to meet up with Ink again... He said it's really important..."

Nightmare seemed sort of dumbfounded and confused "are you serious?... Dream, you leave everyday at this point. What is going on with you?"

Dream sighed "Nightmare, it's important... I don't mean to leave everyday... I'm sorry..."

"Fine..." Nightmare sighed. "Guess I'm not the only one who forgets I'm a twin..."

"Nightmare, it's not like that-" Dream started in a sad tone.

"Really?! Then what is it like?! You've been going off somewhere everyday and now you're selling my stuff! I'm starting to think you don't want to live with me anymore!" Nightmare huffed, his short temper quickly acting up. 

Dream teared up a bit "Nightmare, I don't hate you... I promise..."

"Then what's going on, Dream?!" Nightmare glared at Dream but looked back to the road and his eyes widened, suddenly slamming on the breaks. Both of them jolted forward. A different car just barely missed them, but slamming on the breaks caused a sudden impact from behind. They jolted forward again, harder this time. Nightmare felt pain shoot through his skull as he hit it on the steering wheel. A ringing sounded through his head yet he didn't completely pass out.


	10. What About My Brother?

There was a moment of relative silence before Nightmare could collect himself enough to completely shut the car off aside from the hazard lights and look around. It was all like some crazy dream that he thought would never actually happen to him. 

Nightmare quickly noticed his brother unconscious beside him as other people stopped and swarmed around to see what had happened. There was a painful pounding in his skull that kind of made him want to pass out as well. 

Curious and worried voices could be heard all around but they seemed distant to Nightmare. It was as if nothing existed right now besides himself, Dream, and that one stupid argument. 

Nightmare started to get increasingly worried about Dream. 'What if something really bad happened to him? What if he's dead and that argument was the last thing I got to say to him?' He teared up at the thought.

His hands shook as he quickly fumbled through Dream's bag since it was closer, finding his phone. He shakily clicked the emergency call button.

"9-1-1, what's your emergency?" A very calm sounding woman answered on the other side. It made Nightmare sick how calm she was when someone could be dead because of his recklessness. 

His voice shook and was somewhat chocked through tears "I-I got into an accident... I'm okay but my brother won't wake up and I don't know about the other car..."

"Stay calm. Do you know where you are right now?" The lady didn't seem fazed at all by Nightmare's worry. 

Nightmare quickly looked around them for anything to say but his vision was blurred and he couldn't really think straight "I-I don't know..." Tears traced his cheeks and his worry only got worse as time went on. 

"Alright. We've tracked your number and help is on the way. Stay where you are" the woman calmly responded. 

"W-what about Dream?... What about my brother?..." Nightmare only hoped with his entire life force that he would be alright.

"Did you check if he is breathing? Do not try to move him but you can see if he looks alright." 

Nightmare looked over at Dream with pure worry. The shorter's head was facing the other way but the top right side of his skull was clearly dripping bone marrow. He leaned closer to carefully listen. Dream was letting out soft and shallow breaths, at least letting Nightmare know he was still alive. "H-he's breathing... But his head i-is bleeding b-bad..." Nightmare had never felt so scared before in his entire life. 

"Okay. Do not touch him; he could be seriously injured and moving his head may make it worse. Paramedics should be arriving soon." Nightmare swallowed his fear, trying to stay as calm as he could.

Sirens soon became audible from the distance. A police car and an ambulance pulled up near them as the two policemen ushered bystanders out of the way so the paramedics could get to anyone badly hurt. One of them came up near Nightmare as the other two went to help get Dream out safely.

"Are you alright, sir? Does anything hurt?" The female paramedic asked with seriousness but more care than the lady on the phone.

Nightmare shook his head a tiny bit "j-just a ringing in my skull... I-I'm more worried about my brother?... Will he be ok?..."

"My colleagues are taking care of him. Do you think you can get out of the car safely?" She asked with genuine concern. Nightmare faintly nodded and carefully opened the door. He slowly got out next to the paramedic. She looked him over a little, gently brushing a gloved thumb over a small crack on Nightmare's skull. It wasn't bleeding and not nearly as serious as Dream's. Her hand went back down to her side while Nightmare watched the other two bring Dream up into the ambulance. "Stay here and wait for one of the policemen to talk to you."

Nightmare shook and held himself. He really wanted to go with Dream but knew he had to stay here and couldn't get out of it. His gaze hesitantly went over to the other car that had hit them. A familiar face stood, talking to one of the policemen. 'Error?' Nightmare seemed sort of dumbfounded.

Error seemed much more calm than him as he explained what happened to the policemen, answering all of their questions. He seemed unharmed and glanced at Nightmare for a second. 

Nightmare looked away again, keeping his gaze at the ground while one of the policemen walked over.

"Were you the driver of this vehicle?" The policeman asked simply, seeming to take down notes.

"Yes sir" Nightmare nodded and answered honestly.

"Do you have a valid license on you?"

Nightmare nodded again but shivered "it's in my bag in the back seat..." The other officer had come over now and the first one signaled for him to search for it, not letting Nightmare leave that spot until he had more information.

"Can you tell me what happened here?"

"Yes... I got into an argument with my brother; the other passenger in the car... I took my eyes off the road for a bit and had to slam on the brakes... It was my fault, officer..." Nightmare felt tears still stinging his eyes as he looked the officer in the face. 

"And you take full responsibility?" The policeman wrote something on the note pad he was carrying with him. His partner handed him Nightmare's license and he looked it over to make sure it was valid.

"Yes sir..."

"And you do understand what this means? You will have to pay for the damage to both vehicles and anyone hurt. Plus, you will get many points on your license. I hope this is the first and last time this happens or else your license will be revoked."

"I understand, officer..." Nightmare nodded.

"Ok... You're lucky that young man has no injuries and was the only person in that car. Hopefully your brother comes out alright or else we will have to go into further detail with you." Nightmare frowned, knowing what he was trying to say. 

The second officer spoke "Our enforcement team will keep up to date with you and we will have to tow your car. You cannot drive it any more today. You or someone else can come and get it fixed tomorrow. We will need to take the keys, sir." Nightmare handed the keys over without question.

"You will have to give us your insurance information and bring any out of pocket money to our office by this time tomorrow or else we will have to come and find you again." The first policeman handed Nightmare back his license after writing a few things down. "Since you cannot drive, we can take you to your home if needed."

Nightmare frowned "am I allowed to get my phone from my bag?..." The first officer glanced at the second, whom went to find Nightmare's phone. He handed the phone over and Nightmare just held it. "Can you take me to see my brother?..." 

The first policeman nodded softly "we can take you to the hospital's waiting room but they will decide if you can see him yet. We still have to talk with the other driver again, so you may wait in the back of the squad car." Nightmare nodded and did as told.


	11. Short-Term Effects

**Notes for the Chapter:**

> Effects? Affects? Eh, whatever

Nightmare nervously shifted in his chair. He hated having to sit in this uncomfortably busy waiting room full of sick people and worried families. His thoughts wouldn't stop racing on and on about Dream. The man at the front desk had said that it was too early and they had to thoroughly check over Dream's wound before letting anyone in.

Nightmare stared at Dream's phone, since he'd still had it in his pocket. Dream's voice seemed to echo through his skull, making tears prick at his eye sockets. 'Nightmare, I don't hate you... I promise...'

He gripped the phone tighter as his vision blurred and a few tears fell onto the screen. Nothing else mattered to him right now. It was as if his whole world had stopped and would never go back to normal unless Dream got better. 

Memories... Bad memories wouldn't leave Nightmare alone: All of the times that he'd hurt Dream. The constant, impaired vision. The pain in having to watch as his body would practically tear worlds apart. It wasn't him... But he felt like it was... The awful blackness of the dark consuming him and bearing down on his soul. The physical pain everyday and every night as he paid for what he had done...

Dream was the only one that could stop that pain of the corruption... 

Nightmare was terrified... More than just his pure love for his brother... He was scared that without him, without his magic, the corruption would come back... He'd be forced to watch again as everything he had and everyone he loved got torn apart by himself...

'I don't hate you... I promise...' Dream's voice blended in with his younger self as many tears dripped from Nightmare's tightly closed eye sockets. 'I promise... I will find a way to help you, brother... I know I can... There has to be a way...'

"Nightmare?" A kind woman's voice called out from near the front desk. 

Nightmare slowly looked up and attempted to wipe the tears from his eyes, new ones immediately replacing them. He stood and walked over somewhat slowly. He was scared to hear what had happened. 'What if she tells me that Dream is dead?...'

The woman gave him a sort of serious look with a faint smile "you may come back and see him now." Nightmare silently nodded but couldn't stop his crying. She led him down a hallway and stopped in front of a room somewhere near the middle of the hall. The door was already open a bit, but Nightmare hesitated before stepping in. 

Dream was laid on a bed in the middle of the room with a bandage around his skull and his eyes still closed. A couple machines were around him, tracking his vital signs. Nightmare slightly exhaled in relief at the jutting lines on one machine, showing a normal heartbeat. 

The nurse that had brought him there joined him in the room "he has not yet woken up, but he should soon. There is a minor fracture in his skull. It doesn't appear to be terribly affecting his brain, so no long-term damage aside from a crack left by the fracture. However, the impact might have short-term effects on his memory or abilities to tell things apart."

Nightmare was barely able to nod before quickly going up to the bed. Tears continued to trace his cheeks as he kissed Dream's hand and held it close. He whispered many "I'm sorry"s within his crying, feeling like this was all his fault. 

The nurse stepped out of the room again to give Nightmare some time alone with his brother. There was a long moment of silence, Nightmare's soft sobs and the beep of Dream's heartbeat being the only noises in the room. 

A very weak groan came from Dream's teeth as his eyes slowly fluttered open after a while. Nightmare immediately perked his head up as happier tears dripped off of his chin. "You're awake!" He quickly hugged his brother, being careful of his injuries.

Dream's eyes widened and he weakly attempted to push Nightmare away "what are you doing?!" Nightmare let go and gave a look of pure hurt and regret. Dream looked extremely shocked and confused about the whole situation. "Where am I right now?..."

Nightmare's tears fell again and he shook "Dream?... D-do you know who I am?..."

"I..." Dream looked Nightmare up and down. "Don't think so..." He winced and lightly touched his bandages. "Why does my head hurt so much?"


	12. I'm Sorry

**Notes for the Chapter:**

> Still angsty but really heartfelt brotherly love.

Nightmare pulled back from Dream and held himself. He shook and shut his eyes tightly as if he'd suddenly wake up and none of this would be real... Nothing changed as he let out soft sobs.

Dream felt bad even though he had no idea why Nightmare was crying "did I do something wrong?... I'm sorry... I didn't mean to make you cry..." He sat up but had to shake off some dizziness from doing so.

A doctor took one step into the room and Nightmare almost immediately went up to him. Tears still streamed down his face as he spoke "he lost his memory. The n-nurse said it was short-term. Please tell me it will wear o-off!" 

The doctor seemed taken aback but calmed "none of his symptoms should be long-term. Though I cannot tell you when he will be back to normal. It could take somewhere between a few hours to a few months."

"Months!?" Nightmare freaked out a bit. "No, no, no; he can't forget me for a few months! Please tell me that's rare!"

"I'm sorry but it all just depends on the person and the severity of the injury. I can tell you that, looking at his records, I estimate it will take a few days to a few weeks. However I could be very off. I apologize" the doctor replied calmly. Nightmare couldn't stop crying and it was really starting to get on his nerves how calm everyone else was. 

"What are you talking about?..." Dream asked softly, very confused. "I... Lost my memory?..."

The doctor walked up to him while Nightmare sort of curled into himself "I'm afraid so. You got into a car accident and hit your head against the dashboard. There is a small fracture in your skull but it should feel completely normal after about a week or two."

"How did that happen?..." Dream gently touched his skull again, wincing. 

"That man over there was the driver you were with. He claims to be your twin brother" the doctor gestured vaguely towards Nightmare.

"Twin?..." Dream looked over at him and frowned. 'That must be why he is so upset...' Nightmare couldn't help listening in on what they were saying but kept his gaze on the ground and his mouth silent. 

"Yes. It says that you got into an argument right before the collision and he took his eyes off of the road." Nightmare frowned when the doctor said that, thinking Dream would be upset with him.

Dream looked back to the doctor. He felt bad that he couldn't remember anything, knowing how awful Nightmare must feel right now. "Will I remember everything soon?..."

"I cannot guarantee that, but if you want to remember, then you can try first listening to what people say and see if anything sounds familiar to you. But do not try to force it; your memory should fully come back eventually" the doctor faintly nodded.

Dream silently sighed and nodded back. The doctor quickly checked over the machines and wrote some things down on his clipboard, starting to ask Dream questions about how he felt.

Nightmare slowly was able to control his tears and sniffled, wiping them away as best as he could. The doctor walked past him to leave again. 

"Hey..." Dream hesitantly spoke to Nightmare. "I'm sorry I can't remember..."

Nightmare looked over at him with a frown "no... I-it's not your fault... You don't have to be sorry..." He slowly stood up straight and stepped closer to the bed again.

"I... Really wish I could remember you..." Dream fidgeted with his hands. "What's your name?..." 

Nightmare sighed softly since Dream couldn't even remember that "I'm Nightmare... And you're my older brother, Dream..." Dream just listened silently, waiting for a moment until Nightmare continued. "We've lived together our whole lives... Except for a little while... You're an astrology teacher at a high school, and I'm a history teacher there. We always go to and from the school together and stick together all of the time. You usually drive us everywhere, but this was one of the only times you let me do it... I'm sorry..."

Dream frowned softly "it's ok... You didn't mean to... I can tell you really do care... I'm sorry I still don't remember you, but I believe you... About everything..."

Nightmare stood next to the bed and hesitantly offered a hug. Dream lightly smiled and hugged him. They stayed like that for a moment before Nightmare pulled back. Dream winced when a sudden pain jolted through his wound though nothing touched it. Nightmare gave a worried look at his brother, scared that he might have accidentally bumped it or something. 

Dream curled up slightly and held his head in pain. Nightmare saw his heartrate go up. He quickly pressed the button for the nurse, extremely jumpy and worried about his brother. 

She soon came in the room and went up to the bed "is everything alright?"

"It hurts..." Dream whined softly while tears pricked at his eye sockets. "Please make it stop... Make things go back to normal..."

"I can't do that; I'm sorry. Let me go get the doctor" the nurse turned back around to call for more people. Nightmare frowned and moved back out of the way. He sat down as the doctor and nurse came back to see what was wrong. 

Nightmare pulled his phone out of his pocket and turned it on: four missed texts, all from Killer. He faintly smiled at that as he read them over.

(3:28)Killer: hi Mr.Nightmare 

(4:01)Killer: hello?

(4:36)Killer: are you ok?

(4:49)Killer: did something happen?

Nightmare silently sighed and replied back.

(5:56)Mr.Nightmare: sorry. Things got a bit crazy but I'm ok. I don't think we can meet up tonight...

(5:57)Killer: what happened? 

(5:57)Mr.Nightmare: I got into an accident on the way home but I'm ok. I'm at the hospital with Dream right now.

(5:57)Killer: omg! is Dream ok?

(5:58)Mr.Nightmare: there are a few things... But he should be ok soon...

(5:58)Killer: a few things?

(5:59)Mr.Nightmare: I'll tell you about at later

(5:59)Killer: ok...

Nightmare frowned and looked up at Dream again. The doctor was standing between them, making Nightmare unable to see what was happening. His gaze shifted back down again and noticed Dream's phone in his pocket still. He pulled it out and gazed at the screen: five missed calls, all from some unnamed phone number. Whoever it was clearly wanted to get a hold of Dream badly.


	13. Just Something That We Have To Wait For

Nightmare stayed at the hospital overnight and called Dream and him sick to work. He only vaguely explained what had happened to the principal. 

They spent hours just talking about their lives and the past; well Nightmare did as Dream gladly listened. Dream occasionally got those random spells of pain throughout the day but they would wear off after a bit. It was the second day they'd both stayed at the hospital when the nurse came in with an all too familiar face. 

Killer still had his backpack on as he gazed into the room with a worried look. Nightmare smiled at seeing him again while Killer hesitantly walked in "Mr.Dream?... I heard what happened... Are you doing ok?..."

Dream sat up and looked over at Killer. He looked him up and down for something, anything to come to him... Nothing. "Oh, um, hello..." 

Nightmare sighed softly "Dream, this is Killer. He is one of your best students and he cares about you."Killer looked between them, confused why Nightmare had to explain that.

Dream smiled softly "ok... Hello, Killer."

"Hi?..." Killer walked closer, only getting more worried.

Nightmare noticed and gently explained "Dream injured his skull... He can't remember anything right now... It might be a while before he does..." Killer frowned. "I've been staying with him until he does remember or feels better at least... So, I'm sorry we haven't showed up recently."

"Don't be sorry, Mr.Nightmare" Killer quickly dismissed the apology, definitely not wanting to make this about him. "I totally understand why you would stay here. I really just came to make sure you're both ok..."

Nightmare smiled genuinely "we're ok for the most part... Things should be back to normal soon enough..." He lowered his voice to mumble to himself "hopefully..." 

Killer heard him and frowned "when do you think you can get out of the hospital?..."

"The doctor said that we should be fine as long as these sudden pain-spells stop..." Nightmare looked at Dream with concern but Dream just smiled to show that he was ok.

"That's good..." Killer looked down and rocked on his heels slightly. A feeling of discomfort fell over him. He felt like he didn't really know Dream well enough that he should be here right now. More than anything, he really just came here to see Nightmare again... Though he did care a lot about Dream and their situation. 

A somewhat akward silence rung through the room before Dream perked up and looked to Nightmare as if something just suddenly came to his mind. "I..." He couldn't seem to find the right words. "You... Look kind of like a thought... I-in my head... But... Bigger- not like bigger, but like, older... A kid..."

"A kid?" Nightmare asked with hope. "What does the kid look like?" 'Is his memory coming back?'

"Like... I... I can't remember... I-it only happened for a second..." Dream looked down in sort of shame, feeling bad that he couldn't hang onto that memory for longer. "I'm sorry..."

Nightmare silently sighed but smiled still "it's ok, Dream. Don't be sorry. It will come back to you eventually." 

Dream frowned "yeah, but I just wish I could hold onto it now... I feel bad that I can't remember you... You must have meant world to me..." He tried to keep his emotions in check, still avoiding eye contact. 

Nightmare gently put a hand on Dream's shoulder "stop blaming yourself... This is just something that you have to wait for- that we have to wait for..." 

Killer shifted again but wasn't sure if it was more polite to dismiss himself or just stay. He stood still since he honestly didn't know what to do in this situation.

Dream sighed but reluctantly nodded "it just feels like I should know this stuff but I don't... I'm sorry..."

"Stop apologizing" Nightmare somewhat smiled.

Dream slightly smiled back "heh, sorry." They both faintly chuckled and smiled at each other. It was nice that they could still comfortably talk with each other, even with this effect on Dream's memory.

Nightmare turned to look at Killer and at least include him a little "sorry, Killer. I hope we aren't making you feel akward."

"No, it's alright... I just don't mean to be in the way..." Killer fidgeted a bit. 

"You're not in the way" Nightmare reassured simply.

"Ok..." Killer was hesitant. He still felt sort of uncomfortable and like he shouldn't be there. "I should probably head home anyways... I hope things will get better soon... Thanks for letting me check in with you at least..." 

Nightmare nodded softly "alright... If things go well, we should be back at the school in a few days." 

Killer nodded in understanding and smiled softly "bye Mr.Nightmare. Bye Mr.Dream."

"Bye Killer" Nightmare smiled back sweetly, though he knew he made him feel akward.

"Goodbye" Dream lightly waved and sighed. He was still a bit disappointed in himself for not remembering well. Killer gently smiled and turned to leave. 

Nightmare looked back at Dream with a sigh, nuzzling him a tiny bit "it's ok... You'll remember soon... I promise..." 'Please let my promise mean something...'


	14. The Substitute

**Notes for the Chapter:**

> The sub is a bitch...

It was the first monday since the accident and Killer eagerly went towards the history classroom, hoping more than anything that Nightmare and Dream would be back by now. His smile faltered when he saw the strict substitute teacher sitting in Nightmare's desk. He lowered his head and slowed over to his desk.

Killer set his stuff down before sitting and silently flipping through his personal notebook with a sigh. He gazed over the many sketches of Nightmare. Most were just of his head or the waist up since Killer often didn't have time and wouldn't finish his drawings. They were actually very detailed and realistic for quick sketches.

Ink had always said that Killer was a really good artist; he just needed to care about what he was drawing. And he definitely cared about Nightmare more than anything else. 

Flipping through the pages was like seeing into Killer's entire heart. A soft blush dusted his cheekbones but immediately spread more when he came across a specific page. He'd always hid this one as much as he could and never dared to look at it during school, but he couldn't help staring. 

Nightmare was drawn fully with an extremely dominant, bdsm-esk outfit. He gripped a leash tightly in his right hand that trailed off the edge of the page as if it were attached to the person looking at the sketch. His eyes were demanding with a look of pure lust and love while he bit his bottom lip sexually. 

Killer insanely blushed and quickly closed the notebook, hiding his face against it. He rested his forehead on his desk as if trying to disappear.   
A familiar and annoying laugh came from the desk beside him when Undyne sat down "what'cha doing there, teacher's pet? Sad that you can't suck up to the sub?" 

Killer tried his best to ignore her, keeping his head down. That nickname had easily spread and it was especially common for Undyne to say. He'd kind of become used to it at this point and got much better at not linking it to his little fantasies.

The second bell rang and the substitute immediately stood with a rude and strict presence. She seemed to glare at the entire class "everyone turn in you homework. Anyone that didn't finish it will get zero points for this assignment. You have no excuse. You had the entire weekend to do it." Killer frowned but looked up and stood, having managed to get rid of his blush. He went over with everyone else to the front of the class after hiding his notebook in his backpack. The sub glared again "do so orderly! No pushing or double lines!" 

Killer just did as told so he wouldn't get in trouble, standing in the back of the line and gently setting his paper down on the stack. He went back to his desk in complete silence. 

The substitute nodded once at everyone turning in something, finished or not. She turned and the chalk was pressed hard against the board which made an even more awful sound than normal. Many students cringed at the noise but kept quiet.

"You will be reading from the textbook and answering the review questions on looseleaf paper. Those who don't finish it in class will have to read it for homework" she underlined the white lines that spelt out page numbers: 35-50. Only one student dared to speak out.

"Are you serious?! I thought teachers were supposed to teach us, not make us teach ourselves! At least our normal teacher tried to make history interesting!" Undyne huffed out of turn.

The substitute glared harshly at her "do NOT speak if you are not called on!"

"Oh, I'm sorry, I didn't realize this was elementary school! We're seniors! Just lecture us if you have to! I'm not reading all of that bullshit!"

"That's it! Principals office! Now!" The substitute snapped.

"Fine!" Undyne pushed her desk forward and stood, making a scene. "At least she's nicer than you!" She gladly grabbed her bag and stormed out. 

There was a moment of stunned silence before the substitute practically growled to all the other students "get to reading!"

Killer immediately took out his textbook and opened it. He mentally sighed, cowering down in his seat. 'I really, really wish Mr.Nightmare was here...'


	15. Wednesday

**Notes for the Chapter:**

> Here, have some not angst

Killer begrudgingly walked into the history room; It had been the same substitute every single day since Nightmare had decided to stay at the hospital with Dream. However, Undyne thankfully got suspended, at least for a few days. 

Killer still showed up early despite the bad teacher. He kept his head down in somewhat fear of the sub, trying to just make it to his desk as fast as he could, in hopes that he wouldn't get noticed even though he was the only student in the classroom so far.

"Hello Killer" a soft and all too familiar voice spoke.

"Mr.Nightmare!" Killer perked up and smiled insanely bright, practically diving to hug him. Nightmare chuckled softly at the younger's enthusiasm and smiled as he hugged back. Killer stayed like that for a moment before pulling back. He blushed softly from being so forward with hugging him "heh, sorry Mr.Nightmare..."

"It's really alright, Killer. I'm happy to see you too" Nightmare chuckled sweetly.

Killer looked down slightly "how's Mr.Dream?..."

Nightmare silently sighed "he still isn't perfect with everything, but he's getting better. He seems to remember me now and a lot about himself... He's just not one hundred percent back to normal yet..." 

Killer nodded softly in understanding and looked back up at Nightmare with a wide smile. "I'm really happy you're back. The substitute... Wasn't very nice..." 

Nightmare frowned a bit when Killer said that "oh... I'm sorry. I didn't get to choose who it was... I promise I won't be gone for that long again... At least not anytime soon." 

Killer nodded again "it's alright! I'm just glad you're back." He lightly hugged Nightmare once more before going to sit down, in a much happier mood.

Nightmare watched Killer with a soft smile before turning to his desk again. He shuffled through papers to find the attendance sheet and put it on a clipboard. Groups of kids started filing in and talking to each other.

The bell soon rang and Nightmare stood. His eyes scanned over the classroom while writing down anyone gone. He set the sheet down again before picking up a piece of chalk. His hand wrote easily across the board, happy to be able to do this again.

Nightmare turned back to the class and smiled "I'm glad to hear that most of you behaved while I was gone. Now, today we will be talking about culture. More specifically, the big similarities between sections of the middle east."

Killer immediately got out his class notebook to take notes on everything. He had a goal to not daydream today, during everything that Nightmare was saying. Nightmare trailed on as he explained all about the cultures and religions. Killer would gladly be the first hand raised whenever Nightmare asked a question, and he always got it right.

The class soon ended and everyone rushed out like usual. Killer quickly went up to Nightmare with a wide smile on his face once everyone else left.

"So, Mr.Nightmare... Do you think we could get back into the tutoring again?..." Killer asked with a cute, hopeful look.

Nightmare frowned slightly "I... Don't know... Dream is still recovering and I really need to be there for him right now... But I promise we can start it up again soon..."

"Oh..." Killer frowned, "I understand-"

"But" Nightmare quickly talked again, not liking to see Killer sad. "Maybe you can come over tomorrow... if Dream is feeling better." 

Killer's expression lit up in excitement "yay! I'll see you tomorrow then, Mr.Nightmare!" He smiled widely and kissed Nightmare's cheek without thinking. Both of them softly blushed. 

"Okay. I'll see you tomorrow, Killer" Nightmare smiled and waved as Killer left the room in a hurry to catch the bus. Nightmare giggled silently at his cute student, before quickly getting ready to meet Dream at his classroom today.


	16. Like, Together Together?

Killer smiled widely as he texted Nightmare on the bus. It had been another good day now that Nightmare was back at the school, and they might even be able to hang out tonight. He slightly kicked his feet in excitement. Thoughts ran through his head, making him blush faintly and his smile widen. 

'Are Mr.Nightmare and I going to get together? Like, together together? I really hope we can talk a lot. I love his voice so much. He makes me so happy. I wish we could see each other every day outside of school.'

The bus stopped again and Killer stood, grabbing his bag and heading up towards the front of the bus. There were stares and a little bit of giggling between friends yet nothing actually happened. He sighed silently, very thankful for this. All of the physical bullying had seemed to die down while Undyne was gone but Killer figured it would come right back when she did.

His shoes hit the pavement and the bus quickly drove off. His hands fumbled with his keys, opening the door but immediately closing it behind him. He smiled brightly and set down his backpack, starting on his homework. 

Nightmare and Killer texted back and forth until he brought up the idea of Killer coming over again. Killer lit up in excitement at seeing that, quickly replying back that he would love to. He shoved all of his stuff back into his backpack as he stood. His phone vibrated again.

(4:06) Mr.Nightmare: so I'll see you soon then?

(4:06) Killer: yeah

~

Nightmare smiled and set his phone down on the arm of the couch. He sifted through his bag and found a few sheets of paper tattooed with notes and information. They were all typed up neatly in a good serif font and reasonable size. 

Nightmare set the papers beside him before standing. He stretched and quietly muttered to himself "where even were we in the lessons?..." A soft chuckle left his teeth. "I can't even remember." 

Dream's door opened swiftly "hey Nightmare..."

"Hm?" Nightmare turned to look at his brother. "Yeah?"

"That student is coming over, right?" Dream seemed slightly hesitant for some reason.

"Yeah...?" Nightmare gave a slightly worried look. It was strange for Dream to act like this, then again he understands if he's hesitant because he doesn't remember Killer. "Why? Is something wrong?"

"No..." Dream started "I was just wondering what you were going to do..."

"Oh" Nightmare smiled softly. "I've been tutoring Killer. He just hasn't been coming over lately because you haven't been feeling well. We can try to stay quiet if you need us to."

"It's not that... I guess I just..." Dream thought for a moment. "I guess I'm just worried because I don't remember him well..."

"Don't worry Dream" Nightmare stepped closer and gently hugged him, "Killer's a good kid. I don't even know of anything that could happen that you should be worried about. We're probably just going to be in my room, working, the whole time." 

Dream softly smiled and hugged back "yeah... Sorry... I don't mean to sound like I'm judging or assuming anything bad about him..."

"It's okay" Nightmare nuzzled him a little. "You're just anxious. I get it." 

Dream nuzzled back but soon pulled away "I'll just... Be in my room while you guys study- er... teach... learn...Tutor?" 

Nightmare chuckled softly "alright." He smiled sweetly at Dream before he left back towards his room. A knock came from the front door after a few minutes and Nightmare gladly went to answer it.

Killer widely smiled up at the older male "hi Mr.Nightmare!" He adorably rocked on his feet as he held his backpack straps. 

"Hello Killer" Nightmare faintly blushed but tried to shake it off. He stepped aside while Killer happily walked in. "Do you want to study in my room again?" Killer nodded with a soft blush, taking off his shoes.

Nightmare closed the front door again and started down the hallway. Killer trailed not too far behind. They stepped inside and Nightmare closed the door, Killer happily going over to the bed. He sat down and set his backpack on the floor.

"So, I believe we left off on Jerusalem, correct?" Nightmare sat beside Killer. Killer smiled and nodded as he took out his class notebook.

Nightmare went through his notes and information, Killer scribbling down practically everything. His expression was adorable as he gazed up at Nightmare in eagerness to learn. 

Nightmare stopped talking, mid-page. He didn't even quite realize that he was staring at Killer. His mind couldn't focus on the notes anymore because of the younger's pure look. 

Killer tilted his head slightly, like a confused puppy. "Mr.Nightmare? Is everything ok?" He was cut off by Nightmare's loving gaze and blush.

Nightmare eyed all across Killer's face to land on his mouth. He blushed brighter and couldn't help himself, swiftly cupping Killer's cheek as he pulled him into a kiss. Killer's eyes widened but quickly closed. He gladly melted into the kiss. His arms wrapped around Nightmare's neck to pull him even closer, kissing back. 

Nightmare rested his hands on Killer's waist as he soaked in the feeling of the younger's teeth pressed against his. It felt like they were made to fit perfectly together. He hesitated for a moment before cautiously asking for entrance. 

Killer was surprised and had to take a second to really process what was happening. He slowly parted his teeth to let Nightmare in. The older male gladly entered, his tongue quickly greeted by Killer's. He was gentle as he let their tongues softly press together and dance with equal dominance. Everything around them seemed to disapear until it was just them in this moment. 

Slowly, their teeth parted from each other's as the two panted lightly for air. Their gazes met with pure love. Nightmare gently kissed Killer's cheek and nuzzled him. He was practically entranced by the younger boy's innocent expression. 

Killer squeaked cutely in surprise when he felt Nightmare's teeth gently touch his neck. He shuddered "M-Mr.Nightmare?..." Nightmare didn't respond, peppering many soft kisses across Killer's neck. He held Killer close still as he lightly glided his tongue against the sensitive vertebra. 

Killer shivered and let out a hot breath at the feeling. He shifted a little, letting out a soft groan when Nightmare started gently nibbling. Nightmare nipped and kissed across Killer's neck as he searched for his sensitive spot. 

Killer's breath hitched and he involuntarily let out a quiet moan when Nightmare found it. Nightmare immediately paid more attention to that spot, sucking and nibbling rougher.

Killer crumbled under Nightmare's touch like putty in his hands. He moaned shakily and leaned closer as the older slowly pulled back again. 

Nightmare sweetly kissed the mark he had made, nuzzling into the crook of Killer's neck. Killer shivered but smiled and closed his eyes in content happiness. They simply stayed like that for a while before Nightmare pulled away. 

"Killer..." Nightmare whispered lovingly. "I love you..."

Killer smiled "I love you too, Mr.Nightmare." He thought for a moment and looked Nightmare in the eyes again. "Hey, Mr.Nightmare..."

Nightmare sweetly smiled back at him "yes Killer?" 

"Are we... A thing?" Killer blushed while giving a hopeful look. 

Nightmare couldn't help but blush "if that's what you want... Then I'd love to be in a relationship with you." 

Killer's smile widened and he tightly hugged Nightmare "of course it's what I want! I've loved you for so long, Mr.Nightmare!"

Nightmare chuckled and held Killer close "good..."


	17. That Actually Happened!

**Notes for the Chapter:**

> This is kind of just a filler chapter...

Killer smiled as he curled up against Nightmare's chest. He felt safe and happier than he's ever been before. There was a gentle knock on the door, making him jump and gently push away from Nightmare. 

The door creaked open slightly as Dream looked in "sorry, I don't want to interrupt... But it's getting kind of late and I wanted to know if you guys are hungry..."

Nightmare smiled softly "I guess so. Killer, do you want to stay for dinner?"

Killer hesitated. He didn't want to be a burden. Their food was theirs and he had his own so he figured it would be better to not. "Oh... I didn't realize it was that late already. I should actually probably get going home. Sorry." 

Nightmare mentally sighed but softly nodded in understanding "okay. But you are welcome to join us anytime really." 

Killer nodded "I know..." He started to pack up his things. "Thank you for having me over, though. Maybe we can do this again soon." He stood and put his backpack on. "I'll see you tomorrow Mr.Nightmare." 

Nightmare stood after him and smiled sincerely. He kind of wanted to hug Killer or give him a kiss goodbye, but Dream was watching and he was honestly afraid of what he might think. Killer smiled back at him as Nightmare waved "alright. I'll see you tomorrow then. Bye Killer."

Killer glanced at Dream before heading out "bye Mr.Nightmare. Bye Mr.Dream." He slipped his shoes back on, having them loosely tied enough so he could just slip them on and off easily. The door was closed behind him as he started down the sidewalk. It was a really nice day out with nobody else outside, close to him. 

Killer smiled as his mind trailed back to the kiss. He blushed and giggled silently to himself. Just the thought of their tongues dancing together made Killer feel all fluttery and excited. The apartment buildings got close and Killer quickly went inside. He tossed his backpack and flopped down on his bed. A soft giggle and squeal of fangirling excitement left his teeth.

'That actually happened! Mr.Nightmare kissed me! Kissed my neck! It felt so perfect! Stars, I love him more than anything! I just want him always happy, no matter what! I wish I could serve him so he wouldn't have to worry about any silly little things...'

Killer sighed dreamily at the thought and gripped his pillow. He cuddled it close like it was a person. His face nuzzled up to the soft pillow as he happily giggled to himself. He closed his eyes in joy and content. The room was silent aside from his occasional giggles of happiness. 

Killer soon grew hungry and a bit tired, getting back up to find something to eat. He rummaged through his pantry, then the fridge. Nothing necessarily interested him but he opted for some leftover spaghetti. It microwaved quickly but Killer took his time to eat it. The clock read 7:28 by the time he had finished, though he didn't really have anything else to do tonight. 

Killer yawned softly and went to take a pleasantly warm shower before heading to bed early. He cuddled up to his pillow again as he closed his eyes, convincing himself that it was Nightmare. A gentle smiled crossed his mouth while slowly dozing off to dreams of his beloved teacher.


	18. People Were Staring

Killer brightly smiled as he walked into the history classroom, Nightmare waving at him. He set his backpack on the floor before sitting himself down in the chair. Thoughts still clouded his mind. These things have been bothering him all day... People had been staring at him more than usual. He mentally sighed but just brushed it off.

The bell for the beginning of class rang but the door swung back open almost immediately after it did, making everyone look in that direction. "Guess who's back!" Undyne smiled widely as she strut over to the desk beside Killer. Nightmare rolled his eyes at her making a scene. He just shut the door again and started attendance. 

Killer kept his head down, gaze on his desk. He mentally cursed. His greatest enemy was back from being suspended. Things just went from the best day because of Nightmare, to the worst day because of Undyne. 

Undyne softly chuckled and leaned back in her chair as Nightmare wrote on the board. He turned back to everyone "alright. As of today, you will all be starting individual projects. I will give you a chance to pick what region you will be researching, but if things get too hectic then I will choose for you. You will have to create a presentation about the culture and unique facts about that region. How you present it is your choice: PowerPoint, poster board, anything really. However, you will have to present it to the class and be able to answer any questions that I might ask, so be prepared. I will put up this list of all the possible regions and you will have to sign up for them. If there is more than one person to a region, the first person signed up will get it." 

Killer gently smiled. He enjoyed making projects, but actually presenting them to the class would prove difficult. The thought of being laughed at was too strong for him to speak clearly when he was standing up there. He stayed at his desk while everyone else hurried so they wouldn't be stuck with some unknown place. 

Killer honestly didn't care where he would be researching so he figured he'd just be stuck with whatever was left. He stayed back at his seat and, to his surprise, Undyne did too. She chuckled softly to herself as she looked over at him. 

"Y'know, I'm surprised. I never thought anyone would ever like you" Undyne snickered. "You probably paid them to be honest. Ha! What a lonely little loser." 

Killer tilted his head a tiny bit in confusion and looked over at Undyne. He gently sighed as he broke the rule he made for himself to ignore her. "What are you talking about?..."

"That" Undyne stated simply and pointed at Killer's neck with a smirk. 

Killer blushed and felt over where she said. He flustered 'd-did Mr.Nightmare leave a hickey?! How did I not notice this yet?! This must be why people were staring...' He struggled for a good answer but ended up just saying nothing. 

Undyne chuckled at seeing Killer get flustered and stood, going up to choose her region. Killer silently whined to himself and pulled his hood up to hide the mark. He slowly started towards the sheet once most people had sat back down. He gazed at the only region left. It didn't seem at all familiar: some little island called Cyprus. Killer just wrote his name down and glanced over at Nightmare 

Nightmare smiled softly at Killer who blushed brighter and hid his face. Nightmare's smile faltered and he mentally sighed 'what is up with him now?... I guess I'll ask after class.' He explained more about the project before dismissing them to work quietly.

Killer looked up pictures of the beautiful island and some information, starting to gather sources. The bell sounded overhead after just a few minutes.

"Have a good weekend. Killer can you please come up here?" Nightmare gently asked. Killer flustered but did as he was told. He shoved his things in his backpack before walking up to his desk. Nightmare waited for the other students to leave and lightly put a finger under Killer's chin, having their eyes meet. "What's wrong, Killer?" 

Killer faintly sighed and gazed up at Nightmare. He mumbled under his breath, too quiet for Nightmare to hear. Nightmare just waited until Killer slowly looked away again. The younger pulled his hood down and tilted his head a little. 

Nightmare blushed at the dark hickey he'd left. He chuckled lightly in a somewhat nervous way. "Heh, sorry Killer..." 

Killer gently smiled and rested his head back normally "it's ok, Mr.Nightmare... I liked it... It's just... Other kids m-made fun of me for it..." He sighed and looked down slightly. 

Nightmare frowned and hugged Killer "I'm sorry that happened... I can talk to them if you tell me their names." Killer shook his head no, hesitantly. "I... Don't remember... But I know Undyne did... She always does..." He mumbled the last part in hopes that Nightmare wouldn't hear. As much as he hated her, he knew saying something more would be like a death wish to her 'gang'. His arms wrapped around Nightmare's torso while he hid his face against the taller's chest. 

Nightmare rubbed his back sweetly to calm him down more. He did hear the last part but said nothing else about it. Time seemed irrelevant as the two held onto each other in comfortable silence, their eyes closed. 

Killer very slowly let his arms fall back to his sides and pulled his head back from his teacher's torso. He smiled lightly up at him but his eyes widened when he saw the clock over his shoulder "the bus!" Killer pushed away a bit and scrambled for all of his stuff. Things almost fell in the rush but he kept everything close, his pencil in his mouth as he hurried out, commenting a muffled "goodbye Mr.Nightmare!"

Nightmare laughed softly to himself at that. He whispered to nobody in particular "I hope he doesn't miss the bus... Cutie."


	19. Are You Doing Anything This Weekend?

Nightmare gently sighed in content as he slung his bag over his shoulder. He mentally prepared to be snuck up on by Dream again before turning around. Surely enough, he came face-to-face with his brother right away. "Hey Dream."

Dream smiled softly "hi. Ready for the weekend? I can't believe it's the end of the week already. Everything seemed to go so fast." He shrugged and chuckled "whatever."

"You seem happy" Nightmare pointed out as he started out of the room. 

Dream followed next to him "I'm always happy."

"Good point" Nightmare silently laughed, letting Dream win the silly excuse for an argument. "So, any plans for the weekend, then?" He glanced at his brother for a second before looking back to where he was going.

"Actually, yeah! I talked to someone today that I actually remembered... for the most part. It was nice. He said I could come over tonight or tomorrow and just talk. I figured he could help get my thoughts back in order." Dream lit up happily.

"That's good. Do you remember their name?" Nightmare smiled a bit. It was reassuring to hear that Dream was getting more of his memory back. Hopefully things will all settle down soon.

"I'm pretty sure his name is Cross" Dream seemed slightly uncertain of that. 

"Cross?" Nightmare looked over at Dream quizzically. "The gymnastics teacher?"

Cross and him had never really hung out before, at least from what Nightmare knew. Yes, they see each other at school board meetings and such, but... 

Come to think of it, Nightmare has noticed them looking at each other during the meetings sometimes. 

He would usually zone out during those types of things. Thankfully, vice principle Temmie's high pitched voice kept him from falling asleep, so he never got caught not paying attention. But actually listening to what she was saying was difficult. It was often hard to take her seriously with the way that she talks. Sadly, they all had to take orders from her, since the actual principle rarely left his office. Some of the students even believe that Temmie is the full principle of the school. Nightmare honestly can't blame them, after all, she is the one they get sent to whenever somebody says "to the principal's office".

"Yeah, I think so. He's really nice and promised to help with my memory" Dream smiled sweetly. 

Nightmare was kind of on the fence to trust Cross with something like this. If anything happened to Dream, he didn't know what he would do. They've been really close since they were little. Maybe it was a twin thing. Either way, Nightmare doesn't know Cross very well and wasn't sure what he's really like. 

"Alright... And you're planning on going to his place?" Nightmare asked as they reached the car. 

Dream nodded "he said that would be the easiest. I was thinking about going tomorrow and finishing up some work tonight."

"Ok" Nightmare just simply dismissed the conversation, not wanting to sound pushy or overprotective of Dream. He got in the passenger seat with his bag at his feet. It was actually kind of unnerving to get in a car sometimes, after the accident. Nightmare silently made an agreement with himself to not be the driver again for a while. He had a bit of anxiety that something could happen again if he did, but kept it to himself.

Dream climbed into the driver's seat and buckled his seat belt before putting the key in the ignition. They closed their doors in sync.

The drive home was relatively short and uneventful. The two sat in silence for most of the way, though Dream did attempt to make small talk at one point.

Nightmare just took out his phone, to busy himself, so he wouldn't have to talk about the weather or anything. He opened up his texts with Killer. 

(3:24)Mr.Nightmare: hello

(3:25)Killer: hi Mr.Nightmare

(3:25)Mr.Nightmare: are you doing anything this weekend?

(3:25)Killer: nothing besides homework. Why?

(3:25)Mr.Nightmare: I figured we would have a lot of time to actually get you caught up to date with everything. 

(3:26)Killer: like another tutoring session today?

(3:26)Mr.Nightmare: well probably tomorrow. Then there will be more time, instead of just around an hour. 

(3:26)Killer: ok ◠‿◠ 

(3:27)Mr.Nightmare: what time do you think would be best for you? I'm free all day and Dream will probably be out too.

(3:27)Killer: any time works for me. Maybe right after lunch?

(3:28)Mr.Nightmare: sure

(3:28)Killer: so around 1:00?

(3:28)Mr.Nightmare: that works 

(3:29)Killer: ok

(3:29)Killer: I guess I'll talk to you tomorrow then ◠‿◠

(3:29)Mr.Nightmare: alright


	20. 1:00

**Notes for the Chapter:**

> SMUT WARNING   
> uncensored gay smut, you have been warned

By the time 1:00 rolls around, Killer was already up at Nightmare's front door step. The car was gone so he assumed Dream was out of the house like Nightmare had said. He happily knocked on the door and fidgeted with the straps of his backpack as he waited for a response. 

The door opened and Nightmare immediately stepped aside to let Killer in. The younger gladly walked in past his teacher. He took off his shoes and set them against the wall, just like he did the other two times he'd been here. "Hi Mr.Nightmare," Killer turned to look up at him and smiled brightly. 

"Hello Killer," Nightmare smiled back, shutting the door behind them. "Coming to my room again?" Killer just smiled and nodded. He seemed to eagerly wait for Nightmare to lead the way there. Nightmare gladly turned around and started down the hall. He let Killer in first, once he had opened the door. Killer giddily sat cross-legged on the bed, his backpack on the floor. Nightmare quietly chuckled at his cuteness.

A light blush crossed Nightmare's face but he didn't acknowledge it as he sat next to Killer. His blush spread a bit when Killer scooted closer to him. 

Killer smiled widely "so... Where were we?"

Nightmare looked over at his bag, on his dresser, for a second. "I think we were on..." He started as he looked back at Killer, struggling to remember where they were.

"You don't remember, do you?" Killer giggled. He felt more confident, alone with Nightmare like this. The anxiety he usually has at school and in public all seemed like a distant reality. It made him happy to have Nightmare like him like this, just being himself.

Nightmare chuckled nervously "maybe... Heh, I guess I did get a bit sidetracked last time..."

Killer stuck his tongue out playfully "not sure that's the word I would use~" Nightmare's blush spread at Killer's tone of voice. He silently huffed but couldn't get even a little bit upset at Killer, with his adorable expression. 

"Fine, fine. You encouraged it though" Nightmare stated matter of factly. 

"Maybe I did" Killer gave a mischievous grin. "Maybe I'd do it again~" Something about being alone with Nightmare made Killer feel safe to joke around and be a bit cocky. 

"Oh?" Nightmare crossed his arms and raised a brow. "And what's with the cocky attitude all the sudden?"

"I don't know, Mr.Nightmare. What is with the cocky attitude?~" Killer giggled playfully and nudged up against Nightmare's side. Nightmare flustered but kept it together, nudging him back slightly. Killer smirked "I really liked the way you tutored me last time...~" He walked his fingertips slowly up Nightmare's arm, feeling his body get warm. "It felt really nice...~"

Nightmare shuddered at Killer's touch, feeling his pants tighten a bit. He flustered greatly and tried to contain himself. Heat crept up on Nightmare as he shifted where he sat, attempting to hide his erection in a discrete way. 

Killer's irises brightened in excitement when he noticed the heat all around them. His eyes scanned down Nightmare's chest from his face. He could feel his blush and whole body get warmer when his eyes landed on the slight tent in Nightmare's pants. Killer couldn't help but get extremely excited. His fingers slowly dragged down Nightmare's chest and he bit his bottom lip. He could feel Nightmare's toned ectobody through his white button-up, only turning him on more.

Nightmare shuddered again and looked over at Killer. 'This is such a different side of him... God, it's hot...' His eyes flicked down the younger's body, then back up to his face. Killer was sitting in an adorable, and slightly seductive, position. 

Nightmare flinched for a second when he felt Killer's hand trail down to his v-line. 'N-no, we can't...' A faint pang of worry hit him. He hesitated before grabbing Killer's wrist to make him stop. As much as he wanted this, Nightmare could lose his job from sleeping with a student. 

Killer frowned and looked back up at Nightmare's face again, pulling his hand back. He looked away regrettably. "I'm sorry, Mr.Nightmare... I don't know what got into me..." He felt like he really screwed up. Tension mingled with the heat in the air around them. 

"I'm sorry, Killer... I just..." Nightmare found himself debating whether to really tell Killer the whole truth or not. There was a quiet pause before Nightmare spoke again. "It's not that I don't want it..." He quietly sighed. "Killer, I really do love you... But I could lose my job if anyone found out about this..."

"No, i-it's okay... I get it..." Killer couldn't help the tone of hurt that crept into his voice. He stared at the ground for a moment before going to stand up. "I should probably leave..."

Nightmare immediately felt bad "n-no... Don't leave... I..." He internally fought with himself before standing, suddenly holding Killer's skull and pulling him into a kiss. 

Killer's eyes widened and lit up again. He kissed back, wrapping his arms around Nightmare's neck. 

Nightmare pulled back after just a little and pressed their foreheads together in a loving way. His voice was silent and sweet when he talked "maybe... Maybe they don't have to find out..." He blushed darkly.

Killer flustered but smiled insanely wide. He quickly pulled Nightmare into another kiss, locking his arms behind the taller's neck. 

Nightmare kissed back right away as he let his hands trail down Killer's sides, resting at his waist. His ectobody was small and slender. He seemed delicate, as if any injury would leave a mark for a while. Nightmare gently licked his bottom lip, asking for entrance. Killer eagerly let him in. Their tongues clashed together with lust and love. 

Killer pressed his body against Nightmare's, going up on the balls of his feet so he could reach better, since he was quite a bit shorter than him. His blush spread insanely when he felt Nightmare's crotch press softly against his. The sensation made Killer shiver at first. Anticipation washed over him. He gently attempted to dominate the kiss, to see what Nightmare would do.

Nightmare noticed and his instincts took over, immediately pushing dominance in the kiss. Killer gave up right away, gladly letting Nightmare's tongue explore every inch of his wet cavern. A faint moan escaped his throat as he enjoyed the feeling. He purred and sucked on Nightmare's tongue, earning a low groan from him. 

They both panted lightly when they pulled back for air. Nightmare quickly moved to place little kisses across Killer's neck and collarbone. He gently nibbled in some places but wasn't nearly rough enough to leave any marks this time. Killer quietly moaned, tilting his head slightly to give Nightmare more access. Nightmare happily nipped at the new access while still covering it in chaste kisses. 

Killer gripped onto Nightmare tighter. He pressed more against him again, moaning when their erections pushed against each other's. 

Nightmare purred at the feeling. He couldn't help himself, pressing Killer to lay back on the bed and moving to be over him. Killer blushed profusely as he gazed up at Nightmare with an adorably excited expression. 

Nightmare found himself thinking out loud in a whisper. "God, I've wanted to do this for so long~ You're so adorable~" 

Killer cutely squeaked in surprise at that statement. His blush practically consumed him. "Y-you have?" 

Nightmare quickly realized what he had said but didn't deny it at all. "Yes, Killer~" His voice was kind but seductive. 

Killer slightly squirmed under Nightmare to get into a more comfortable position. Nightmare leaned over a bit and softly kissed him again, Killer immediately kissing back. 

The kiss was short lived as Nightmare pulled away and pecked Killer's forehead. "I love you~" 

Killer's eyes lights shimmered, gazing up at Nightmare with a needy expression. This is the closest he's ever been to his teacher and he badly wanted more of it. "I love you too, Mr.Nightmare..." Killer purred silently and squirmed closer to Nightmare. 

Nightmare blushed, pressing back against Killer. He shuddered when he felt their clothed members touch. His erection only grew in need. Killer tried to somewhat grind up against him, biting his bottom lip in hopeful anticipation. 

Nightmare moaned quietly and grinded back. He sort of helped Killer sit up again so he could remove his sweatshirt. Nightmare tugged off the shorter's t-shirt and dropped it aside, gazing at his exposed chest. He smiled and gently kissed Killer's neck, starting to shower many peck across his collarbone. He left a trail of kisses down the middle of Killer's chest until he reached his waist and stopped. 

Nightmare moved to look Killer deep in the eyes, as if asking permission. Killer flustered insanely but nodded. Nightmare hooked his fingers under the waistband of Killer's shorts, slowly pulling them down. Killer shyly looked away. He was a bit insecure about his figure. 

Nightmare noticed and gently smiled "you look beautiful~" 

Killer flustered, letting out a very small moan when Nightmare started tracing his v-line with kisses. His blush spread greatly. "M-Mr.Nightmare~" He put a hand to his mouth, on instinct, to quiet himself. 

Nightmare gently purred and moved up to Killer's face again, bringing his hand away. His voice was caring and soft "have you ever done this before?~" 

Killer looked away in slight embarrassment, not wanting to answer. "Um... O-once..." He felt bad admitting that he wasn't still a virgin. It was actually a while ago and he wasn't the most comfortable talking about it. 

Nightmare didn't seem at all upset or anything, though he never really imagined he would be the only virgin in the relationship at first. He smiled sweetly "it's up to you how far we go, ok?~ I don't want you uncomfortable~" 

"O-Ok" Killer nodded softly. Nightmare very gently ran his hand down Killer's chest. He trailed a finger slowly up the younger's member, drawing a moan out of his throat. Killer shuddered and his member twitched at the teasing touch. He let out a hot breath, tugging at Nightmare's shirt to show he wanted it off. 

Nightmare pulled back just enough to take off his top. He was slow, unbuttoning it one at a time, from top to bottom. Killer let out a low whine. Nightmare smirked as he pulled the shirt off and tossed it onto the floor. He dipped down to kiss Killer's neck as his hands traveled up his chest again, letting his thumbs drag over his nipples teasingly. 

Killer moaned, the moan quickly turning into a whine "M-Mr.Nightmare~ P-Please don't tease me~" Nightmare hummed pleasingly at Killer's whines. The sounds egged him on, starting to drag him into his dom space. He bit his bottom lip but listened to Killer. His hand lightly grasped the younger's hard-on, wiping his thumb over the tip. 

Killer shifted and moaned. "P-Please~ I need you~" he begged. Nightmare smirked as he stood. He undid his belt before hooking his fingers through the side loops of his pants, sliding them off. His member happily sprang free of it's cotton cage and he got over Killer, on the bed. Killer slightly drooled at the sight of Nightmare's erection. He wanted it so badly. 

Nightmare caressed Killer's cheek so their eyes met, giving a caring smile. "You need prep?~" Killer shyly nodded. He wished he could just have Nightmare take him then and there, but he knew it would really hurt. Nightmare kissed Killer softly to show that he would be gentle. 

Killer smiled at that, letting him take over completely. His eyes shimmered with eagerness and love. He blushed when Nightmare put three fingers in front of his face. 

"Suck~" Nightmare's voice was sexually demanding but still had a soft tenderness to it. Killer immediately did as told, taking Nightmare's fingers into his mouth. He closed his eyes with a light groan, sucking on them. His tongue swirled around and between the digits until they were fully coated in saliva. 

Nightmare purred pleasingly as he pulled his fingers out, Killer's eyes fluttering back open. He gently kissed the younger's collarbone in reassurance before tracing one finger around his rim. Killer shivered at the feeling. He uttered a long, drawn-out moan when Nightmare suddenly pressed the finger inside his ass. He squirmed and faintly panted at feeling Nightmare's finger twist inside of him. 

Nightmare blushed a bit brighter from the view he had. He slowly added a second finger. Killer let out another loud moan as he was stretched, Nightmare scissoring his fingers to prepare him. His moans turned into a gasp when Nightmare added the third finger. Nightmare lightly thrusted his fingers and stretched Killer

Killer teared up when he was stretched near what felt like his limit. His moans turned to whimpers from the pain. Nightmare quickly noticed and stopped moving his fingers, kissing away Killer's tears. He slowly pulled his fingers out. 

Killer purred at his teacher's kindness but silently whined. It kind of hurt but it still felt nice and he didn't want it to stop. "M-Mr.Nightmare...~ D-Don't stop...~ Please...~" Killer lightly pants. "I-I need you~" He tried to wiggle closer. 

Nightmare nuzzled his face into the crook of Killer's neck, gently rubbing his member against the shorter's ass. "You think you're ready?~"

Killer drooled in anticipation "yes~ Please, Mr.Nightmare~" He somewhat braced himself, gripping the sheets beneath him. Nightmare purred and carefully pressed the tip inside. Killer's breath hitched. Tears brimmed his eyes as Nightmare slowly sheathed himself. Nightmare let out a hot breath and quiet moan at the tightness. 

Killer whimpered, a tear rolling down his cheek from the pain. Nightmare was so much bigger than he expected. 

Nightmare stopped to let Killer adjust, kissing away his tears lovingly. Killer panted as the pain slowly turned into pleasure. He moaned and bucked his hips a little as a signal for Nightmare to move. 

Nightmare gently smiled, starting to thrust at a slow speed. Killer moaned and closed his eyes in pleasure. He gripped the sheets more tightly. "Ah!~ F-Faster!~" 

Nightmare gladly obliged, thrusting harder and faster. He couldn't help but let out moans from the feeling of being inside Killer. "F-Fuck~ You're so tight~" A faint pressure started to build inside of him. 

Killer gasped and cried out in pleasure when Nightmare hit his prostate, sending a huge jolt of pleasure through his body. "AH!~ R-Right there, Mr.Nightmare!~" 

Nightmare took note of that, aiming to hit that spot with every thrust. Killer practically screamed in pleasure. His member twitched as it pumped out streams of warm seed onto his and Nightmare's chests. Nightmare moaned and leaned over Killer more, burying his face in the younger's neck before cumming hard inside him. 

Killer gasped and his whole body shuddered at the feeling of being filled. He moaned while Nightmare slowly stopped thrusting. They both panted heavily, coming down from the high. 

Nightmare hummed softly with love and whispered "that felt amazing~" He happily showered Killer's face in kisses. 

Killer purred and relaxed, smiling at the gentle kisses "I love you so much, Mr.Nightmare~" He let go of the sheets and hugged Nightmare as he nuzzled him. 

"I love you too, Killer~" Nightmare mumbled. A small moan came from Killer when he carefully pulled out, laying beside him. He held Killer close and kissed his forehead before yawning. "You mean so much to me~" 

Killer blushed but cuddled up against Nightmare's chest. He smiled as he shyly asked "Mr.Nightmare... Was that your first time?"

Nightmare flustered but nodded honestly. "I wasn't bad, was I?"

"What? Oh, no! Not at all~" Killer nuzzled him. "You were great~ I was just curious~" He yawned.

Nightmare chuckled softly "that's good. I love you, Killer. Get some rest."

Killer purred and snuggled closer, closing his eyes. He didn't even realize how exhausted he was at first but almost immediately fell asleep. Nightmare smiled and rubbed Killer's back with a yawn. He kissed the top of Killer's head once more before dozing off with him. 'Goodnight... My little kitten~'


	21. I don't need anything

Nightmare yawned as he woke up. He felt Killer shift in his arms and smiled. Killer was curled up against Nightmare's chest, cuddling as close as possible. Nightmare kissed the top of his head and whispered very quietly "so cute... I love you, Killer..." 

The sound of a door closing came from the hallway, making Nightmare tense but relax. 'Dream must have come home' he thought and yawned. 'What time even is it?' Nightmare looked over at the clock in his room, being careful not to move too much so he wouldn't wake Killer. 

The clock read around 5:30. 'Oh yeah, it was only two-ish when we passed out... Actually napping was nice though.' He sighed silently and nuzzled Killer.

Killer groaned lightly, blinking awake. He yawned but quickly flustered once his eyes met Nightmare's. Memories of earlier made his face feel extremely hot just thinking about it. Nightmare smiled sweetly at Killer, making him feel helpless under the older's gaze. 

"Good- well, afternoon technically" Nightmare silently chuckled. "Did you rest well?" He kissed Killer's forehead in a comforting way and nuzzled him.

Killer shyly nodded. He had slept pretty well, despite a stinging soreness that he pushed to the back of his thoughts. 

"That's good" Nightmare smiled. "It's around the time I would usually have dinner, if you're hungry. I heard Dream come back but I think he's in his room now." 

Killer's blush spread greatly at the thought of Dream seeing them like this. His stomach growled lowly when Nightmare mentioned dinner, since he hadn't had much to eat today, but he still turned down any of their food. Taking anything that he didn't personally earn felt selfish to him. "No, I'm fine..."

"Are you sure?" Nightmare gave a caring look. "Do you just want some pain medicine or anything?" 

Killer shook his head and buried his face in Nightmare's chest, mumbling "no... I don't need anything..." 

Nightmare gently sighed, knowing Killer was just doing this for him, but didn't push any farther. "Alright," he spoke softly while rubbing Killer's back. "You can't turn down my cuddles though." Nightmare attempted to get Killer to show him a smile again. He caressed the younger's cheek to bring his face up from his chest and have their eyes meet. 

Killer blushed but allowed Nightmare to easily direct his gaze. The older's breath was warm, so close it was like a ghosting kiss. Killer glanced at Nightmare's mouth. He half-expected to get a kiss, though he didn't want to initiate it himself. 

Nightmare pulled back but smiled sweetly. "Well I am hungry... I'll tell you what, you can stay in here and go back to sleep if you want. I'm going to get something to bring back and eat in here. I can clean our clothes on the way too."

Killer quickly shook his head, immediately trying to justify why he did. "W-we didn't really get them dirty." He flustered from his own words "we took them o-off before they could get anything o-on them..."

Nightmare sighed "ok. I'll be right back though." He kissed Killer's forehead before standing and going over to his closet. He quickly slipped on some pants and a long-sleeve black shirt. Killer couldn't help but stare and blush a little. He had never seen Nightmare in something besides a button-up before, especially something so casual. 

Nightmare looked back at Killer and noticed him staring, letting out a soft chuckle. "What? Did you think I don't have shirts like this?" 

Killer flustered "n-no... I guess it just slipped my mind." He sat up on the bed, feeling the blanket shift to lay just below his waist, exposing his naked rib cage and spine. 

Nightmare smiled "you're so cute." He went over to kiss Killer's cheek. Having done everything until now, Nightmare felt safe to do things like this, since he knew Killer wouldn't reject him. "Stay here for now. You can get dressed... or not. I'll be right back." 

Killer nodded in understanding as he watched Nightmare walk out the door and shut it behind him. He gazed around the room. Their clothes were still scattered on the floor but the room was really clean otherwise. 

Most of the mess they had made earlier just ended up on or... Inside Killer. With his ectobody desummoned, it was simply gone. Since their external bodies are made purely of magic, it all absorbs back into their souls when they get rid of it. He shuddered somewhat excitedly at the thought of Nightmare's magic swirling softly with his. It wasn't much and would soon be absorbed by his own, but Killer enjoyed the moments it was still there.

He stood shakily, having to catch his balance on the bedside table thanks to how sore he was. His footing stuck and he was able to walk easily again. The open room felt chilly compared to the warmth of the bed. 

Killer picked up his clothes from the floor, pulling them all on. His eye lights looked around the room as he hugged his sweatshirt around himself. 

It was quiet and kind of lonely without Nightmare next to him. The room was really big and empty compared to the one in his own apartment. He curiously walked along the walls of the room, taking in all of the things he could see: a clock, Nightmare's bag, a book shelf with many stories and maps. 

Killer peeked into Nightmare's closet. He was right about one thing, at least. There were a lot more button-ups than anything, but he still had other types of shirts as well. Killer noticed a design on one of the t-shirts and got curious. He went to push aside a few of the shirts to see what it was. The hangers moved easier than expected, making Killer stumble as he put too much pressure on the slide. he grabbed onto the nearest object from instinct to make sure he didn't fall over. His hands only reached the t-shirt he was trying to see. It immediately slipped off of its hanger. Thankfully, the wall wasn't too far behind, so Killer could catch himself without making much noise. 

The now empty hanger swung on the pole that was used to hang it. It hit the wood shelf above, causing it to fall onto the ground, getting knocked off the pole. Killer tensed up at all the sudden movement. He pressed back into the wall as much as he could while trying to calm down again. 

'Oh no... Mr.Nightmare is going to yell at me for messing around with his stuff...' Killer held the t-shirt in one hand, leaning over to pick up the hanger with his other. He heard the door open and froze for a moment.

Nightmare set his food on the dresser and went over pretty quickly. He sighed gently once he could fully see the situation. His expression seemed relieved. 

Killer flustered and tried to explain. "I'm sorry! I was just curious about your shirts since I'm thinking about it now, but the hangers didn't work how I thought they did. I was trying to look at this t-shirt but I tripped and accidentally pulled it off, and-" 

Nightmare laughed quietly "it's fine, Killer. Don't worry about it." He paused for a second. "But next time, you should just ask first. I would have showed you."

Killer looked away in slight guilt. He held the shirt and hanger close to his chest. "Sorry, Mr.Nightmare... I promise I won't look through your things without permission again." 

Nightmare smiled "thank you. Don't get too upset though. You didn't do anything wrong. You were just curious." He took the clothes from Killer and nuzzled him. "I'll put these back for you." 

Killer shyly nodded and looked down in apology. "I should probably go home anyways..." 

Nightmare raised a brow at him "really? You aren't bugging me if that's what you're thinking. I want you to stay, so don't worry about that. I never mind you staying longer, Killer." He hung the shirt back up before turning around and caressing the younger's cheek. "I love you, ok?" 

Killer blushed "I love you too... Thank you." 

"Of course. You mean so much to me, just as I've told you before." Nightmare sweetly pecked a kiss on Killer's teeth. "Please stay for a little bit longer... I want cuddle with you."


	22. A Regular Thing

Killer quietly sighed. 'How long have we been laying here?' He shifted a tiny bit in Nightmare's arms to look up at his face. Nightmare's eyes were closed, his expression relaxed but happy. Killer blushed softly. 'Did he fall back asleep cuddling me?...'

The room was silent and calm. It felt oddly comforting, but Killer already knew that it must be really late by now. He carefully tried to pry himself back from Nightmare's chest and gently shook him. "Mr.Nightmare?... Please wake up..." 

Nightmare quietly groaned but blinked his eyes open. He yawned and smiled softly at Killer, his voice a bit groggy from sleep. "Hm? What is it, Killer?"

"It's really late... You fell asleep again... I have to leave now, or I could get in trouble..." Killer gently pulled out of Nightmare's arms. 

Nightmare sighed "alright... I love you, y'know..."

Killer smiled sweetly "I know, Mr.Nightmare. I love you too." 

Nightmare reluctantly let go of Killer and sat up, stretching with another yawn. The younger stood and readjusted his clothes. He happily hugged Nightmare once he was standing, gently kissing his cheek. 

There was a knock on the bedroom door and Killer almost panicked. He took a deep, quiet breath before letting go the hug. Nightmare sighed and stood, walking over and opening the door. 

Dream stood there with a sort of tired or annoyed look on his face. "What's wrong?" Nightmare asked kindly. 

Dream just shrugged "I've got a light headache. I was hoping you'd know where the Advil is." 

Nightmare nodded "it's in the bathroom mirror." 

Killer looked between them before grabbing his backpack from the floor. He slung it over one of his shoulders and tried to walk around the two. "I should get going." He yawned "I'm tired and I need to get some good sleep since I have stuff to do tomorrow." 

"Alright... That was a good study session today. I actually found it quite fun." Nightmare smiled sweetly at Killer, who nodded. 

"I did too" Killer quickly agreed with a nod. 

"Maybe we could make this a regular thing..." Nightmare offered, trying his best not to blush in front of Dream. 

Killer immediately flustered at that and hid his face "Y-Yeah... I'd like that." He shifted his bag on his back and gently pushed past them, into the hall. "I'll see you some other time, Mr.Nightmare. You too, Mr.Dream." His voice got quieter as he stepped away towards the front door. He slipped his shoes on quickly and left without another word, shutting the door behind him.

Nightmare silently sighed, mumbling since he had already left "goodbye Killer..." He turned his attention back to his brother and just stared for a second before going down to the bathroom and opening up the mirror cabinet above the sink. He pulled out a little bottle of pills and handed it to Dream. "It's always here, for future reference." The house fell silent aside from Dream's quiet thank you and Nightmare felt an incredibly akward aura surround them. 

'I do not have to tell Dream anything right now' he reminded himself. They both just stood there for a moment before Nightmare left back to his room, mentally cringing at what had just happened. He shut his door and relaxed a little. His room felt empty and lonely now after getting to spend so much time with Killer. A sigh left Nightmare's teeth as he sat back on his bed and turned to lay face down. 

His voice was muffled in his pillow as he sort of talked to himself. "Killer is so adorable... I wish I could see him like that all the time... I hope he knows what I meant about making that a regular thing..." A light purr of happiness came from Nightmare's throat. "God, he looked so submissive and cute..." 

~

Killer shut and locked the apartment door behind him and immediately leaned back against it, panting softly from running home. He slid down to be sitting on the floor, dropping his backpack beside him. The pure silence around him made his soulbeat seem louder with each thud in his chest. 

"Mr.Nightmare said we should do that regularly! Did he mean... Th-that?! That was... So amazing! He's so dominant but caring, and... God he's perfect..." Killer exhaled with a smile. "I don't deserve a man like him." He curled up a bit, happily. The smile that stretched across his face felt like it would never dissolve. Nothing could change how completely elated he felt right now; Nothing.

**Notes for the Chapter:**

> Sorry I haven't been updating! I have one more week of pure testing, then I'm out of school for the summer, so hopefully I can write more then.


	23. Fluffy Birthday Oneshot

**Summary for the Chapter:**

> This is pretty much unrelated to the normal plot of the story. It's just a short fluffy little one shot that I decided to put in here since it's my birthday and I wanted to do something birthday related with these two cuties. I'm working on the next real chapter too so you can just skip this if you want.

Killer giggled like a child hyped up on sugar. He quickly knocked, fidgeting with the ribbon on a neatly wrapped box in his hands. The smile on his face spread insanely wide when the door opened to show Nightmare standing on the other side.

Nightmare opened his mouth to ask why Killer was here but was interrupted before he could even get word out. Killer stretched the present out towards his teacher excitedly "Happy birthday Mr.Nightmare!"

"Oh" Nightmare blushed slightly. "Thank you. You really didn't have to get me anything, Killer." 

"But I wanted to! You mean so much to me and you deserve all the gifts you want!" Killer bounced on his heels, eagerly waiting for Nightmare to open his gift. 

"Here, why don't you come inside" Nightmare said, taking the box and stepping aside so Killer could walk into the living room. The younger immediately did as he was told and took off his shoes for courtesy sake. Nightmare closed the door behind them and sat on the couch. 

"Sorry I didn't get anything for Mr.Dream..." Killer looked away in guilt for a split second before looking back. "But I didn't know what he would want." He stood close to the couch but didn't sit down, wanting to completely see Nightmare's face when he opened the box.

"I understand" Nightmare smiled and nodded. "He isn't here right now anyways. He's having a birthday dinner with Ink and Blue and such. I said I didn't want to come. I've never really been a fan of public celebrations." He set the present in his lap and started to undo the bow on top. It untied like a shoelace and the box simply had a cover to take off instead of needing to be unwrapped all the way. 

Killer watched intensely as Nightmare took the cover off. He lit up and smiled at Killer "thank you!" Nightmare pulled out a brand new horror movie he's never seen before and a homemade bracelet that was laying on top of the CD case. He looked over the beading on the bracelet. There were letters on the beads that spelled out 'my everything' and it had a small heart bead right after that. He opened his arms to offer a hug, almost tearing up from the sweet gift. 

Killer immediately wrapped his arms tightly around the other's torso. "I'm glad you like it. It took me a while to find all the specific beads I needed. I hope it fits right. The string is a little stretchy so it should." 

"I love it" Nightmare smiled and nuzzled Killer, kissing his cheek. 

Killer blushed and giggled, returning the gesture. "I love you, Mr.Nightmare." 

"I love you too, Killer. I'm so happy to be able to call you mine. You mean the world to me. YOU are MY everything." 

Killer flustered and buried his face in Nightmare's chest. His soul fluttered like a million butterflies. "Mr.Nightmare don't say that..." 

"Aw why can't I? I'm just telling the truth" Nightmare chuckled, rubbing Killer's back. "You're the best boyfriend I could ever dream of." 

Killer whined in embarrassment "I'm not that special."

Nightmare cupped Killer's cheeks and moved his head away from his chest so he could look him face to face. "Killer, listen to me. You are very very special. Everything about you is unique in a good way. Nobody has the same idea of perfect, but to me you are the most perfect being there is. So don't talk down about yourself like that. You are amazing and I love you more than anything. Never forget that." 

Killer could barely keep it together, practically melting from Nightmare's words. "O-ok..." He blushed brightly. Nightmare set the box and movie aside, putting the bracelet on and pulling Killer onto his lap. Killer squeaked cutely in surprise but quickly relaxed and cuddled up in Nightmare's arms. "Thank you Mr.Nightmare... Happy birthday..."

Nightmare smiled, kissing the top of Killer's head sweetly. "You are the best birthday gift I could ever ask for." He closed his eyes in content, resting his chin on Killer's skull. They both snuggled closer and it felt like they could happily just cuddle like this for hours on end.

**Notes for the Chapter:**

> Ok, now back to the actual story haha.


	24. About Saturday

**Notes for the Chapter:**

> Gah, it's been forever! This is a really short chapter but I've been having trouble leading into plot ideas I have without just copping out and using a bunch of time skips without explanations.

It was Monday again. Though Killer and Nightmare didn't stop texting back and forth with flirts and little compliments over the rest of the weekend, it still felt like they had been apart for weeks now. Killer had to force himself to not run as the bell rang for the end of seventh period. He couldn't stop thinking about the older male all day, hardly being able to focus in any of his other classes. 

After the first bell rang there was five minutes before they were expected to be in their next class. Killer couldn't help fast-walking downstairs from his math room. He hugged his personal notebook tightly against his chest as he weaved past other students towards room 169: Nightmare's classroom. 

A couple people were still just leaving when Killer arrived, since he had practically jogged through the halls. He smiled insanely wide and walked swiftly to his seat, setting down all of his stuff. 

Nightmare quietly chuckled when he saw Killer enter and slightly waved at him. Killer blushed a little. He didn't want to really approach him right now since other students were filing in and out of the room, but he knew they'd get to talk after class. 

The hour seemed to go by pretty fast since they weren't really doing anything today. Killer hadn't even checked the time, sketching in his personal notebook all period. He did often glace up at Nightmare but didn't seem to register the clock behind him. 

The end of the day bell rang after what felt like only fifteen minutes. The noise in the room instantly rose since it was a "silent work day" and everyone else was waiting to talk with their friends. Killer noticed but simply kept sketching, acting like he hadn't heard the bell so he could stay after class without looking suspicious. 

As soon as everyone had left the classroom, Killer looked up from his notebook. He was ready to rush over to Nightmare, but jumped in surprise when he saw Nightmare already right next to him. 

"M-Mr Nightmare!" Killer slammed his notebook shut and blushed profusely. 

Nightmare softly chuckled "sorry, Killer. I didn't mean to scare you." He leaned against Killer's desk a little as he spoke, somehow making this all seem so natural with his casual stance. 

"I-it's ok" Killer stuttered, forcing himself to lean the opposite direction, shoving his personal notebook into his backpack. The room fell silent. 

Nightmare cleared his throat to break the slightly tense air. "So, did you want to talk about Saturday?..." A purple blush lightly dusted his cheeks. 

"I-I guess..." Killer flustered. He swallowed his nervousness before asking, "Wh-what did you mean when you said we should make this a r-regular thing?" 

Nightmare's blush darkened at the question, his expression slightly embarrassed. "Oh, that..." He chuckled kind of nervously. "I just meant that we should spend some more time together... Not studying." 

"Like... A-a date?" Killer's eye lights glimmered like an excited puppy. 

"Yeah," Nightmare nodded quickly in agreement, "some real dates. Maybe a night in or something..." He wanted badly to say a night out instead of in. Perhaps they could go for a picnic or to a theater together one day, but Nightmare didn't quite want share their relationship yet. 'It's probably best to keep it a secret.' He thought to himself. 

Killer suddenly found himself hugging Nightmare. To be honest, he was so excited that he didn't even notice when he had wrapped his arms around the older male; It just naturally happened. "I'd love that," Killer smiled and rested his head gently against Nightmare's chest, listening to the soft soulbeat that came from inside. 

Nightmare smiled and hugged back lovingly. "Me too, Killer..." He happily sighed. He was content just holding Killer in his arms forever, but he knew it was the end of the day and Killer probably had to head home. His grip slowly loosened as he let go of the hug. "You should probably head out. You always have to catch the bus anyways, don't you?" 

Killer reluctantly pulled back after a moment. He smiled up at Nightmare and chuckled softly "I probably already missed it. I can walk though."

"Are you sure?" Nightmare gave a slightly worried expression. "Isn't your house a long ways away? I'm sure Dream wouldn't mind taking you home today." He felt bad that Killer always walked home after they spent time together. 

"I'm fine," Killer nodded. "It'll be nice to have some time to just think. Besides, it's good for me. I need to get some more fresh air every now and then." 

Nightmare frowned "oh... Do you have something on your mind that you need time to think about?..." All that came to his head at Killer's wording was that their new relationship was troubling him. 

Killer paused in surprise "what? No. Did I say something like that?..." The room quickly fell silent again. He sighed "I'll see you tomorrow, ok? Goodbye Mr.Nightmare."

Nightmare relaxed once more, with a smile. "I look forward to talking more about that date idea." He winked and quietly chuckled, making Killer blush deeply. 

Killer shyly nodded in agreement. He felt frozen in place as if he was temporarily paralyzed by Nightmare's wink. 

A soft laugh left Nightmare's teeth. "Goodbye Killer." He waved and picked up his bag. "You can't just stay here alone. If you stare any longer you might just have to take me up on that ride offer." 

Killer blinked, shaking himself back to reality. "Oh, right. Sorry Mr.Nightmare" he replied quickly. A brisk wave was all Killer added before making his way out of the school and towards his house. He only glanced back once in the hall, seeing how close Dream already was to the classroom.


End file.
